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| Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#2
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Sony TV - Picture Problem
Have you done what Jeff suggests ?
kip "Bruce H" wrote in message ... Correction to post: "Bruce H" wrote in message news:... Based on his description (problem shows for a while then screen disappears) the protection circuitry is kicking in to blank the picture. A loose connection (or bad solder joint) can definitely cause this. If not a solder joint problem, it is doubtful that a component failure problem would allow him to get a normal picture to submit. I have a Sony KP-41T15 that has a similar "line paring" problem but in my case there are faulty components in the vertical circuit as the problem condition is continuous from when the set is turned on. The vertical voltage feed to the jungle IC is below what it should be (approx 3V versus 3.6V). I am suspecting the jungle IC as well but first I have to find the problem components(s). Bruce "Shoreline Electronics" wrote in message ... Resolder your vertical output IC561. This will solve your problem. Resolder the Horizontal Driver Transformer while your in there for good preventive maintenance -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "John F Miller" johnATenosoft.net wrote in message ... Hello, I have a Sony Trinitron KV27S22 (December 1997). A couple of days ago, it developed a picture problem. Rather than try to describe it, I have placed the following photos on the web: Image of color bars: Behaving OK - http://www.enosoft.net/kv27s22/Bars%20-%20OK.JPG Image of color bars: Exhibiting problem - http://www.enosoft.net/kv27s22/Bars%20-%20Problem.JPG The problem will set in anything from a few seconds to a few minutes after cold-starting the set. The problem will persist for a few seconds before the display completely disappears. Only a cold reset will restore the image. Audio is fine. I have done some troubleshooting and have narrowed the problem to what I think is a capacitance issue. Using a painter's stick (wooden!), I tapped the various components on the main board and found that the tapping could induce the problem. However, if I hold the ground of the audio connectors, the tapping does not create the problem. When the problem is present, grabbing the ground of the audio connector clears the problem. The most sensitive part of the board is shown at: http://www.enosoft.net/kv27s22/Main%20Board%20(Part).JPG I have a copy of the Sony service manual for this set but, before I merrily begin replacing all the capacitors, I would like to know if anyone knows a specific cause and/or that I am barking up the right tree. Many thanks in advance, John Miller. |
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#3
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Sony TV - Picture Problem
Jungle IC301 CXA1477 is your line pairing culprit.
Best place to buy these are from B & D http://www.bdent.com/ Original Sony IC's in Original Sony packaging. Around $50.00 Yeah...you can scrounge them up for $20 or so here and there.....but once ya ya bit by a bad one or one that lasts a couple days....OEM is the only way to go on these. -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "Bruce H" wrote in message ... Correction to post: "Bruce H" wrote in message news:... Based on his description (problem shows for a while then screen disappears) the protection circuitry is kicking in to blank the picture. A loose connection (or bad solder joint) can definitely cause this. If not a solder joint problem, it is doubtful that a component failure problem would allow him to get a normal picture to submit. I have a Sony KP-41T15 that has a similar "line paring" problem but in my case there are faulty components in the vertical circuit as the problem condition is continuous from when the set is turned on. The vertical voltage feed to the jungle IC is below what it should be (approx 3V versus 3.6V). I am suspecting the jungle IC as well but first I have to find the problem components(s). Bruce "Shoreline Electronics" wrote in message ... Resolder your vertical output IC561. This will solve your problem. Resolder the Horizontal Driver Transformer while your in there for good preventive maintenance -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "John F Miller" johnATenosoft.net wrote in message ... Hello, I have a Sony Trinitron KV27S22 (December 1997). A couple of days ago, it developed a picture problem. Rather than try to describe it, I have placed the following photos on the web: Image of color bars: Behaving OK - http://www.enosoft.net/kv27s22/Bars%20-%20OK.JPG Image of color bars: Exhibiting problem - http://www.enosoft.net/kv27s22/Bars%20-%20Problem.JPG The problem will set in anything from a few seconds to a few minutes after cold-starting the set. The problem will persist for a few seconds before the display completely disappears. Only a cold reset will restore the image. Audio is fine. I have done some troubleshooting and have narrowed the problem to what I think is a capacitance issue. Using a painter's stick (wooden!), I tapped the various components on the main board and found that the tapping could induce the problem. However, if I hold the ground of the audio connectors, the tapping does not create the problem. When the problem is present, grabbing the ground of the audio connector clears the problem. The most sensitive part of the board is shown at: http://www.enosoft.net/kv27s22/Main%20Board%20(Part).JPG I have a copy of the Sony service manual for this set but, before I merrily begin replacing all the capacitors, I would like to know if anyone knows a specific cause and/or that I am barking up the right tree. Many thanks in advance, John Miller. |
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#4
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Sony TV - Picture Problem
Thanks for the link, Jeff! I'll get around to this and report back (some
time after I replace the plumbing in my house and install the insulation on the exterior walls). So far all the supply voltages seem to be approximately where they need to be but I may have a leaky transistor. Don't want to bug anyone until I do some proper investigation... Bruce "Shoreline Electronics" wrote in message ... Jungle IC301 CXA1477 is your line pairing culprit. Best place to buy these are from B & D http://www.bdent.com/ Original Sony IC's in Original Sony packaging. Around $50.00 Yeah...you can scrounge them up for $20 or so here and there.....but once ya ya bit by a bad one or one that lasts a couple days....OEM is the only way to go on these. -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "Bruce H" wrote in message ... Correction to post: "Bruce H" wrote in message news:... Based on his description (problem shows for a while then screen disappears) the protection circuitry is kicking in to blank the picture. A loose connection (or bad solder joint) can definitely cause this. If not a solder joint problem, it is doubtful that a component failure problem would allow him to get a normal picture to submit. I have a Sony KP-41T15 that has a similar "line paring" problem but in my case there are faulty components in the vertical circuit as the problem condition is continuous from when the set is turned on. The vertical voltage feed to the jungle IC is below what it should be (approx 3V versus 3.6V). I am suspecting the jungle IC as well but first I have to find the problem components(s). Bruce "Shoreline Electronics" wrote in message ... Resolder your vertical output IC561. This will solve your problem. Resolder the Horizontal Driver Transformer while your in there for good preventive maintenance -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "John F Miller" johnATenosoft.net wrote in message ... Hello, I have a Sony Trinitron KV27S22 (December 1997). A couple of days ago, it developed a picture problem. Rather than try to describe it, I have placed the following photos on the web: Image of color bars: Behaving OK - http://www.enosoft.net/kv27s22/Bars%20-%20OK.JPG Image of color bars: Exhibiting problem - http://www.enosoft.net/kv27s22/Bars%20-%20Problem.JPG The problem will set in anything from a few seconds to a few minutes after cold-starting the set. The problem will persist for a few seconds before the display completely disappears. Only a cold reset will restore the image. Audio is fine. I have done some troubleshooting and have narrowed the problem to what I think is a capacitance issue. Using a painter's stick (wooden!), I tapped the various components on the main board and found that the tapping could induce the problem. However, if I hold the ground of the audio connectors, the tapping does not create the problem. When the problem is present, grabbing the ground of the audio connector clears the problem. The most sensitive part of the board is shown at: http://www.enosoft.net/kv27s22/Main%20Board%20(Part).JPG I have a copy of the Sony service manual for this set but, before I merrily begin replacing all the capacitors, I would like to know if anyone knows a specific cause and/or that I am barking up the right tree. Many thanks in advance, John Miller. |
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#5
Posted to sci.electronics.repair
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Sony TV - Picture Problem
Just a follow up to my television problem (Sony KP-41T15).
I bought the Jungle IC from B & D and it solved the problem. Interesting that the plastic in this set is very fragile and cracks easily. I used slivers of ABS pipe and ABS/PVC solvent to repair cracks. My next task is to set the convergence (particularly the red CRT gun as I had to replace it). Swapped the yolk and positioned it as close to the original as possible. Everything works except the picture is a little out. Just wanted to say thanks for the information. Bruce Bruce H wrote: Thanks for the link, Jeff! I'll get around to this and report back (some time after I replace the plumbing in my house and install the insulation on the exterior walls). So far all the supply voltages seem to be approximately where they need to be but I may have a leaky transistor. Don't want to bug anyone until I do some proper investigation... Bruce "Shoreline Electronics" wrote in message ... Jungle IC301 CXA1477 is your line pairing culprit. Best place to buy these are from B & D http://www.bdent.com/ Original Sony IC's in Original Sony packaging. Around $50.00 Yeah...you can scrounge them up for $20 or so here and there.....but once ya ya bit by a bad one or one that lasts a couple days....OEM is the only way to go on these. -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "Bruce H" wrote in message ... Correction to post: "Bruce H" wrote in message news:... Based on his description (problem shows for a while then screen disappears) the protection circuitry is kicking in to blank the picture. A loose connection (or bad solder joint) can definitely cause this. If not a solder joint problem, it is doubtful that a component failure problem would allow him to get a normal picture to submit. I have a Sony KP-41T15 that has a similar "line paring" problem but in my case there are faulty components in the vertical circuit as the problem condition is continuous from when the set is turned on. The vertical voltage feed to the jungle IC is below what it should be (approx 3V versus 3.6V). I am suspecting the jungle IC as well but first I have to find the problem components(s). Bruce "Shoreline Electronics" wrote in message ... Resolder your vertical output IC561. This will solve your problem. Resolder the Horizontal Driver Transformer while your in there for good preventive maintenance -- ========================== Jeff Stielau Shoreline Electronics Repair 344 East Main Street Clinton,CT 06413 860-399-1861 860-664-3535 (fax) ======================== "John F Miller" johnATenosoft.net wrote in message ... Hello, I have a Sony Trinitron KV27S22 (December 1997). A couple of days ago, it developed a picture problem. Rather than try to describe it, I have placed the following photos on the web: Image of color bars: Behaving OK - http://www.enosoft.net/kv27s22/Bars%20-%20OK.JPG Image of color bars: Exhibiting problem - http://www.enosoft.net/kv27s22/Bars%20-%20Problem.JPG The problem will set in anything from a few seconds to a few minutes after cold-starting the set. The problem will persist for a few seconds before the display completely disappears. Only a cold reset will restore the image. Audio is fine. I have done some troubleshooting and have narrowed the problem to what I think is a capacitance issue. Using a painter's stick (wooden!), I tapped the various components on the main board and found that the tapping could induce the problem. However, if I hold the ground of the audio connectors, the tapping does not create the problem. When the problem is present, grabbing the ground of the audio connector clears the problem. The most sensitive part of the board is shown at: http://www.enosoft.net/kv27s22/Main%...d%20(Part).JPG I have a copy of the Sony service manual for this set but, before I merrily begin replacing all the capacitors, I would like to know if anyone knows a specific cause and/or that I am barking up the right tree. Many thanks in advance, John Miller. |
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