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
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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