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Samsung Microwave & GE Microwave oven
I found the following thread using Google but found it difficult to reply so
I copied the thread. It follows my message. My GE microwave oven started acting up about 2 months ago. It has a Samsung microprocessor and this earlier thread seemed close. For seemingly no reason it would start emitting beeps every few seconds. I unplugged it, plugged it back in an it was okay. Then it stopped taking input from the keypad. Unplugging it didn't reset the microprocessor. I took it apart and after removing the circuit board and replacing it, then reassembling it, the oven worked okay for a few days. I thought it might be noise from a bug zapper, the noise having a slope so sharp it might have been mistaken for leaking rf. Wasn't it. I removed all the transistors and capacitors and they tested okay. Whenever I'd take it apart and reassemble it would work for a few days. I didn't want to peel off the keypad because I felt I couldn't return the peeled keypad without it looking pretty bad. I looked at replacement parts and ruled out buying parts. Finally I took the keypad off and exercised it bending it bending it back and forth on each axis. It peeled off nicely and I was surprised! When I returned it there was no visible evidence I had taken it off (but I was careful). The oven has been working flawlessly for weeks now. I suspect maybe I could have bumped into the keypad with something or possible just age, over 6 years old, but it's working perfectly. I'm happy. Bill ------------------------------------------------------------------------ All messages from thread Message 1 in thread From: ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 1997/07/22 I am looking for a place that sales Samsung microwave oven parts. The part is a microwave oven door. The model is Samsung MU3050W. Is there anyone who can point me in the right direction so that I can get cooking again. Thanks jlwing -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet Message 2 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start does nothing (display keeps cycling push start). The beeper will beep reminding that the cycle is over or to push start, just that the key board has no input. The only way to get the keyboard to work properly is to reset the microprocessor by turning the power off or resetting it with the reset pin on the microprocessor. The Microwave was in a flood, even before the original box was opened. It is possible that the microwave was plugged in before it was fully dried out, as when I acquired it, there was still water inside of the keyboard stickers (which I removed and cleaned). The rest of the microwave works fine. I have never seen the display working properly. Also note that I do not have the instruction manual, and there may be something simple that I may be missing, but I doubt that ;-) Thanks in advance for any help in getting this thing to work, as it is in new condition (with a few exceptions!), along with a void warranty, Jeff Message 3 in thread From: Jerry G. ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/23 By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses ============ Message Separator =============== "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle Read the rest of this message... (43 more lines) Message 4 in thread From: Sam Goldwasser ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start Read the rest of this message... (36 more lines) Message 5 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I resoldered half the board in hopes of a bad connection already. Jeff "Sam Goldwasser" wrote in message d.com... A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and Read the rest of this message... (50 more lines) Message 6 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses Read the rest of this message... (75 more lines) Message 7 in thread From: Bonita Lee Geniac ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Read the rest of this message... (69 more lines) Message 8 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/05/01 Thanks everybody. I found the problem - a diode that was going to the keyboard matrix decided to have a reverse voltage break down of 0.8 volts, fooling the computer, and causing the keypad to stop responding. It probably became shorted when the keypad was wet, from an increase in current, since the part of the matrix that the diode was supplying was for all the functions that cause the microwave to enter a cook mode. P. S. if your very careful when peeling the keypad buttons back, and the sticky stuff does not peel off, then there may be a chance that will work fine afterwards - I had mine off 3 times and it works fine. Thanks, Jeff "Bonita Lee Geniac" wrote in message ... Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one Read the rest of this message... (108 more lines) Message 9 in thread From: Trevor Mooney ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 2002-05-04 06:26:07 PST Hi, I have a prob with my Samsung MB245 microwave. some time a go when I plug it in it the touch pad locked up when I set the clock. Then a series of beeps started and wouldn't stop. Now after a long spell sitting in garage when I plug it in the whole display lights up but no response from touch pad. I have my suspicions but would like some Ideas before I toss it. Thanks Trevor |
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There may be a cold solder or cracked trace on the board. If it is a multi
layered board, the fault may be between the layers. It is also possible that there is a defective part, in such a way that when it is disturbed it works for a while longer, and then fails again. As for how they service these, the service centre will change the complete board to service these types of intermittent faults. There would be too much of a loss of time to try to service these at the component level, especially for intermittent faults. -- Jerry G. ========================== "Soyrunner" wrote in message ... I found the following thread using Google but found it difficult to reply so I copied the thread. It follows my message. My GE microwave oven started acting up about 2 months ago. It has a Samsung microprocessor and this earlier thread seemed close. For seemingly no reason it would start emitting beeps every few seconds. I unplugged it, plugged it back in an it was okay. Then it stopped taking input from the keypad. Unplugging it didn't reset the microprocessor. I took it apart and after removing the circuit board and replacing it, then reassembling it, the oven worked okay for a few days. I thought it might be noise from a bug zapper, the noise having a slope so sharp it might have been mistaken for leaking rf. Wasn't it. I removed all the transistors and capacitors and they tested okay. Whenever I'd take it apart and reassemble it would work for a few days. I didn't want to peel off the keypad because I felt I couldn't return the peeled keypad without it looking pretty bad. I looked at replacement parts and ruled out buying parts. Finally I took the keypad off and exercised it bending it bending it back and forth on each axis. It peeled off nicely and I was surprised! When I returned it there was no visible evidence I had taken it off (but I was careful). The oven has been working flawlessly for weeks now. I suspect maybe I could have bumped into the keypad with something or possible just age, over 6 years old, but it's working perfectly. I'm happy. Bill ------------------------------------------------------------------------ All messages from thread Message 1 in thread From: ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 1997/07/22 I am looking for a place that sales Samsung microwave oven parts. The part is a microwave oven door. The model is Samsung MU3050W. Is there anyone who can point me in the right direction so that I can get cooking again. Thanks jlwing -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet Message 2 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start does nothing (display keeps cycling push start). The beeper will beep reminding that the cycle is over or to push start, just that the key board has no input. The only way to get the keyboard to work properly is to reset the microprocessor by turning the power off or resetting it with the reset pin on the microprocessor. The Microwave was in a flood, even before the original box was opened. It is possible that the microwave was plugged in before it was fully dried out, as when I acquired it, there was still water inside of the keyboard stickers (which I removed and cleaned). The rest of the microwave works fine. I have never seen the display working properly. Also note that I do not have the instruction manual, and there may be something simple that I may be missing, but I doubt that ;-) Thanks in advance for any help in getting this thing to work, as it is in new condition (with a few exceptions!), along with a void warranty, Jeff Message 3 in thread From: Jerry G. ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/23 By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses ============ Message Separator =============== "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle Read the rest of this message... (43 more lines) Message 4 in thread From: Sam Goldwasser ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start Read the rest of this message... (36 more lines) Message 5 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I resoldered half the board in hopes of a bad connection already. Jeff "Sam Goldwasser" wrote in message d.com... A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and Read the rest of this message... (50 more lines) Message 6 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses Read the rest of this message... (75 more lines) Message 7 in thread From: Bonita Lee Geniac ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Read the rest of this message... (69 more lines) Message 8 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/05/01 Thanks everybody. I found the problem - a diode that was going to the keyboard matrix decided to have a reverse voltage break down of 0.8 volts, fooling the computer, and causing the keypad to stop responding. It probably became shorted when the keypad was wet, from an increase in current, since the part of the matrix that the diode was supplying was for all the functions that cause the microwave to enter a cook mode. P. S. if your very careful when peeling the keypad buttons back, and the sticky stuff does not peel off, then there may be a chance that will work fine afterwards - I had mine off 3 times and it works fine. Thanks, Jeff "Bonita Lee Geniac" wrote in message ... Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one Read the rest of this message... (108 more lines) Message 9 in thread From: Trevor Mooney ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 2002-05-04 06:26:07 PST Hi, I have a prob with my Samsung MB245 microwave. some time a go when I plug it in it the touch pad locked up when I set the clock. Then a series of beeps started and wouldn't stop. Now after a long spell sitting in garage when I plug it in the whole display lights up but no response from touch pad. I have my suspicions but would like some Ideas before I toss it. Thanks Trevor |
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I'm still convinced I found the problem. If I fired it up with the keypad
in the circuit before flexing it, the display would indicate I should enter the time but keypad presses were ignored. If I fired it up with the keypad out of the circuit all the segments would light then the microprocessor would reset and indicate RESET on the display. My board my have been different than that noted below where the sender felt a diode near the ribbon connector was bad. Actually, the same diode on mine read the same way and continued to do so after I replaced it. Then I realized after looking at the circuit that it was a flyback diode in one of the relay coil circuits. Without the flyback diode the drive transistor turning off could generate a spike which could punch out the drive transistor. Reading the diode in reverse isn't showing a failed diode but the base emitter drop of the drive transistor. No, the problem in my case, and I'd guess his, was in the keypad. Bill "Jerry G." wrote in message ... There may be a cold solder or cracked trace on the board. If it is a multi layered board, the fault may be between the layers. It is also possible that there is a defective part, in such a way that when it is disturbed it works for a while longer, and then fails again. As for how they service these, the service centre will change the complete board to service these types of intermittent faults. There would be too much of a loss of time to try to service these at the component level, especially for intermittent faults. -- Jerry G. ========================== "Soyrunner" wrote in message ... I found the following thread using Google but found it difficult to reply so I copied the thread. It follows my message. My GE microwave oven started acting up about 2 months ago. It has a Samsung microprocessor and this earlier thread seemed close. For seemingly no reason it would start emitting beeps every few seconds. I unplugged it, plugged it back in an it was okay. Then it stopped taking input from the keypad. Unplugging it didn't reset the microprocessor. I took it apart and after removing the circuit board and replacing it, then reassembling it, the oven worked okay for a few days. I thought it might be noise from a bug zapper, the noise having a slope so sharp it might have been mistaken for leaking rf. Wasn't it. I removed all the transistors and capacitors and they tested okay. Whenever I'd take it apart and reassemble it would work for a few days. I didn't want to peel off the keypad because I felt I couldn't return the peeled keypad without it looking pretty bad. I looked at replacement parts and ruled out buying parts. Finally I took the keypad off and exercised it bending it bending it back and forth on each axis. It peeled off nicely and I was surprised! When I returned it there was no visible evidence I had taken it off (but I was careful). The oven has been working flawlessly for weeks now. I suspect maybe I could have bumped into the keypad with something or possible just age, over 6 years old, but it's working perfectly. I'm happy. Bill ------------------------------------------------------------------------ All messages from thread Message 1 in thread From: ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 1997/07/22 I am looking for a place that sales Samsung microwave oven parts. The part is a microwave oven door. The model is Samsung MU3050W. Is there anyone who can point me in the right direction so that I can get cooking again. Thanks jlwing -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet Message 2 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start does nothing (display keeps cycling push start). The beeper will beep reminding that the cycle is over or to push start, just that the key board has no input. The only way to get the keyboard to work properly is to reset the microprocessor by turning the power off or resetting it with the reset pin on the microprocessor. The Microwave was in a flood, even before the original box was opened. It is possible that the microwave was plugged in before it was fully dried out, as when I acquired it, there was still water inside of the keyboard stickers (which I removed and cleaned). The rest of the microwave works fine. I have never seen the display working properly. Also note that I do not have the instruction manual, and there may be something simple that I may be missing, but I doubt that ;-) Thanks in advance for any help in getting this thing to work, as it is in new condition (with a few exceptions!), along with a void warranty, Jeff Message 3 in thread From: Jerry G. ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/23 By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses ============ Message Separator =============== "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle Read the rest of this message... (43 more lines) Message 4 in thread From: Sam Goldwasser ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start Read the rest of this message... (36 more lines) Message 5 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I resoldered half the board in hopes of a bad connection already. Jeff "Sam Goldwasser" wrote in message d.com... A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and Read the rest of this message... (50 more lines) Message 6 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses Read the rest of this message... (75 more lines) Message 7 in thread From: Bonita Lee Geniac ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Read the rest of this message... (69 more lines) Message 8 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/05/01 Thanks everybody. I found the problem - a diode that was going to the keyboard matrix decided to have a reverse voltage break down of 0.8 volts, fooling the computer, and causing the keypad to stop responding. It probably became shorted when the keypad was wet, from an increase in current, since the part of the matrix that the diode was supplying was for all the functions that cause the microwave to enter a cook mode. P. S. if your very careful when peeling the keypad buttons back, and the sticky stuff does not peel off, then there may be a chance that will work fine afterwards - I had mine off 3 times and it works fine. Thanks, Jeff "Bonita Lee Geniac" wrote in message ... Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one Read the rest of this message... (108 more lines) Message 9 in thread From: Trevor Mooney ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 2002-05-04 06:26:07 PST Hi, I have a prob with my Samsung MB245 microwave. some time a go when I plug it in it the touch pad locked up when I set the clock. Then a series of beeps started and wouldn't stop. Now after a long spell sitting in garage when I plug it in the whole display lights up but no response from touch pad. I have my suspicions but would like some Ideas before I toss it. Thanks Trevor |
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It worked for maybe a month then I slammed the door and it stopped. Peeled
it again, replaced it and it works. A new touchpad is something like $55 while a new microwave is near $80. Peeling and resticking is free. What I found that's worked for over 2 months now is when I replaced the touchpad I offset upwards just a little. The top edge is not off just a little bit. It seems fine and works well. I no longer slam the door either. "Jerry G." wrote in message ... There may be a cold solder or cracked trace on the board. If it is a multi layered board, the fault may be between the layers. It is also possible that there is a defective part, in such a way that when it is disturbed it works for a while longer, and then fails again. As for how they service these, the service centre will change the complete board to service these types of intermittent faults. There would be too much of a loss of time to try to service these at the component level, especially for intermittent faults. -- Jerry G. ========================== "Soyrunner" wrote in message ... I found the following thread using Google but found it difficult to reply so I copied the thread. It follows my message. My GE microwave oven started acting up about 2 months ago. It has a Samsung microprocessor and this earlier thread seemed close. For seemingly no reason it would start emitting beeps every few seconds. I unplugged it, plugged it back in an it was okay. Then it stopped taking input from the keypad. Unplugging it didn't reset the microprocessor. I took it apart and after removing the circuit board and replacing it, then reassembling it, the oven worked okay for a few days. I thought it might be noise from a bug zapper, the noise having a slope so sharp it might have been mistaken for leaking rf. Wasn't it. I removed all the transistors and capacitors and they tested okay. Whenever I'd take it apart and reassemble it would work for a few days. I didn't want to peel off the keypad because I felt I couldn't return the peeled keypad without it looking pretty bad. I looked at replacement parts and ruled out buying parts. Finally I took the keypad off and exercised it bending it bending it back and forth on each axis. It peeled off nicely and I was surprised! When I returned it there was no visible evidence I had taken it off (but I was careful). The oven has been working flawlessly for weeks now. I suspect maybe I could have bumped into the keypad with something or possible just age, over 6 years old, but it's working perfectly. I'm happy. Bill ------------------------------------------------------------------------ All messages from thread Message 1 in thread From: ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 1997/07/22 I am looking for a place that sales Samsung microwave oven parts. The part is a microwave oven door. The model is Samsung MU3050W. Is there anyone who can point me in the right direction so that I can get cooking again. Thanks jlwing -------------------==== Posted via Deja News ====----------------------- http://www.dejanews.com/ Search, Read, Post to Usenet Message 2 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start does nothing (display keeps cycling push start). The beeper will beep reminding that the cycle is over or to push start, just that the key board has no input. The only way to get the keyboard to work properly is to reset the microprocessor by turning the power off or resetting it with the reset pin on the microprocessor. The Microwave was in a flood, even before the original box was opened. It is possible that the microwave was plugged in before it was fully dried out, as when I acquired it, there was still water inside of the keyboard stickers (which I removed and cleaned). The rest of the microwave works fine. I have never seen the display working properly. Also note that I do not have the instruction manual, and there may be something simple that I may be missing, but I doubt that ;-) Thanks in advance for any help in getting this thing to work, as it is in new condition (with a few exceptions!), along with a void warranty, Jeff Message 3 in thread From: Jerry G. ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/23 By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses ============ Message Separator =============== "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle Read the rest of this message... (43 more lines) Message 4 in thread From: Sam Goldwasser ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/24 A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and ask to "press start". The relay(s) will shut down properly. The Magnetron transformer relay will cycle on and off according to duty cycle. What does not happen is that once a button that will cause the microwave to enter a cook cycle is pushed, even with all power wires disconnected and direct power to the control board relay, the keyboard's input does nothing - no beep, no functions, no start up after the door switch was activated and shut it off. Start Read the rest of this message... (36 more lines) Message 5 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I resoldered half the board in hopes of a bad connection already. Jeff "Sam Goldwasser" wrote in message d.com... A couple of easy checks would be of the power supply filter caps and for bad connections. --- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/ Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ +Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm | Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html In article "Jerry G." writes: By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. "Da Man" wrote in message ... I have a Samsung Microwave (Model #: MW6470W) that the digital control is malfunctioning on. The display Works fine when first powered up (displays all segments, then SIMPLY SAMSUNG. The clock can be set, and numbers can be entered. All functions seem to be normal until a function is entered (at ANY time) which will cause the microwave to turn on, or the start button, at that point the keyboard freezes (can't change size of proportions, restart it after the door switch was activated, or anything with the keyboard). Basically, the microwave's keyboard will not respond to the next input. The relays operate properly and the display will count down properly when in cook mode (provided that the door switch was closed and was not opened), it will stop if the door switch is activated and Read the rest of this message... (50 more lines) Message 6 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Personal: http://www.total.net/~jerryg Electronic Components, And Navigation Compasses Read the rest of this message... (75 more lines) Message 7 in thread From: Bonita Lee Geniac ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/04/27 Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one particular address, etc. Especially since every other feature works properly (unless it came from the factory that way!). I thought of a pulse/noise entering back through the circuitry from the relays cutting in, but the keyboard freezes before they click on. I may just do some extensive component testing on it when I am really bored, since I don't care if reliability is a big issue because it is my microwave. I also noticed that there are some weird transistor setups driving mostly outputs on the board - probably about 10 to 12 of them that I may pop out and test individually Jeff By your description, this sounds like a fault on the microprocessor board. It can be any of the components in this area that is making it hang up. The most reliable and easiest fix is to change the complete board. -- Jerry Greenberg =========================================== Email: Home Page: http://www.zoom-one.com Components: http://www.zoom-one.com/electron.htm Products: http://shop.affinia.com/jerryg50/Store1/ Navigation: http://www.zoom-one.com/navigati.htm Sci/Inst: http://www.zoom-one.com/actel.htm Read the rest of this message... (69 more lines) Message 8 in thread From: Da Man ) Subject: Samsung Microwave View this article only Newsgroups: sci.electronics.repair Date: 2000/05/01 Thanks everybody. I found the problem - a diode that was going to the keyboard matrix decided to have a reverse voltage break down of 0.8 volts, fooling the computer, and causing the keypad to stop responding. It probably became shorted when the keypad was wet, from an increase in current, since the part of the matrix that the diode was supplying was for all the functions that cause the microwave to enter a cook mode. P. S. if your very careful when peeling the keypad buttons back, and the sticky stuff does not peel off, then there may be a chance that will work fine afterwards - I had mine off 3 times and it works fine. Thanks, Jeff "Bonita Lee Geniac" wrote in message ... Before you go any further, completely disconnect the keypad and locate the matrix diagram for the keypad functions. Then manually program the unit without the keypad by following the matrix. I have never seen a keypad that had been wet or one that someone took apart that would ever work properly again. It sounds much more like a keypad problem than a citcuit board problem. The keypads on recent models are high failure parts anyway. Da Man wrote: Thanks, But I was hoping that I could get around replacing that board, since I would think that it is expensive and may not be worth while :-( - sorta like having to replace a bad magnetron, being it's almost cheaper to buy a whole new microwave. Oh well, I will price a new one any way, or maybe I might get lucky and find another microwave with a good board. The interesting thing is that the microprocessor does not freeze up - it just fails to respond to the keyboard. I find it hard to believe that the microprocessor lost some of it's programming or is damaged in one Read the rest of this message... (108 more lines) Message 9 in thread From: Trevor Mooney ) Subject: samsung microwave View this article only Newsgroups: sci.electronics.repair Date: 2002-05-04 06:26:07 PST Hi, I have a prob with my Samsung MB245 microwave. some time a go when I plug it in it the touch pad locked up when I set the clock. Then a series of beeps started and wouldn't stop. Now after a long spell sitting in garage when I plug it in the whole display lights up but no response from touch pad. I have my suspicions but would like some Ideas before I toss it. Thanks Trevor |
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I have a Samsung mw6470w microwave the problem with it is that it has stopped to heat.
One morning when operated it was doing everything but just not heating the things. Its working normally, all its functions are normal but its not just heating. it has worked very well all these years. No problem at all.....is it all over for it now? Will it be cheaper to buy a new one....Will it worth repairing what is actually wrong with it? I live in Surrey Canada. |
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kinni420 writes:
I have a Samsung mw6470w microwave the problem with it is that it has stopped to heat. One morning when operated it was doing everything but just not heating the things. Its working normally, all its functions are normal but its not just heating. it has worked very well all these years. No problem at all.....is it all over for it now? Will it be cheaper to buy a new one....Will it worth repairing what is actually wrong with it? I live in Surrey Canada. It could be as simple as a bad connection - or almost anything else. Testing will be needed. Given the cost of new microwave ovens, unless it is special in some way, may not be worth fixing. However, you can't do anything about it yourself unless you are experieced in high voltage high power electronics. The inside of a microwave oven can be lethal. --- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/ Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/ +Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm | Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html Note: These links are hopefully temporary until we can sort out the excessive traffic on Repairfaq.org. Important: Anything sent to the email address in the message header above is ignored unless my full name is included in the subject line. Or, you can contact me via the Feedback Form in the FAQs. |
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