Replace / repair the SC board. Check SD, SU boards for shorts
Can you give me any insight on why you would expect it to be the SC board? I see SC is listed as the 1st most common problem for both 4 and 10 flashes but during troubleshooting it had me disconnect the SC20 connection and turn the power on, the blink code stayed at 4 or 10 rather than changing to 6 which led to replacing the SC board or possibly issues with the SD or SU boards.
I can do the SD and SU checks easy enough but I hate to spend more money on another board without something pointing towards that being the problem.
Can you give me any insight on why you would expect it to be the SC board? I see SC is listed as the 1st most common problem for both 4 and 10 flashes but during troubleshooting it had me disconnect the SC20 connection and turn the power on, the blink code stayed at 4 or 10 rather than changing to 6 which led to replacing the SC board or possibly issues with the SD or SU boards.
I can do the SD and SU checks easy enough but I hate to spend more money on another board without something pointing towards that being the problem.
Have you read this thread start to finish?
4 blink is a PSU code. When the SC fails, it's not uncommon for it to short the P-board. That then triggers the 4 blink.
I have seen and read 4 blinks changing to 10 blink after a number of power cycles.
Had you isolated SC2 it would have changed. In fact if you disconnect sc20 and sc2 it'll probably go 7 blinks and if you located Q661 on the lower left heatsink on the SC, I'll be 99% certain it will be dead short allong with 7 other heatsinked IGBTs and surface items
I did read through the rest of the thread but because I had never gotten the 6, 7, or 8 blinks with the SC20 unplugged I didn't think it was the same issue I was having, I was unaware the SC2 also needed to be unplugged. I will check again tonight with both disconnected to see if I get the 7 blinks.
Unplugged both SC2 and SC20 and got 6 blinks, should I still be checking Q661 and the buffer boards for shorts?
yep. Q661 mainly because I expect that shorted and when you find it is, you check the sd/su so that when you have the SC repaired you don't blow it up again.
I tested Q661; G-E was about 21 ohms, E-C was a short, G-C was about 21 ohms. Tested a couple other IGBTs, some has similar results with a shorted E-C. Reading through the other forums I see a few other people with this result and it sounds like that is the problem, am I understanding that correctly?
I tested Q661; G-E was about 21 ohms, E-C was a short, G-C was about 21 ohms. Tested a couple other IGBTs, some has similar results with a shorted E-C. Reading through the other forums I see a few other people with this result and it sounds like that is the problem, am I understanding that correctly?
Hi all, I know this is an old thread but thought I would give it a try. Been going through all the different info posted here and I have a symptom not mentioned. A few days ago when shutting tv off heard a pop, tried to turn back on and no go, just blinking power light. I didn't know this thing had limited self diagnostics with the number of blinks. It must have started at ten blinks because I didn't notice any pattern to the blinks. Googled tc-p50g20 to see what info would come up and I found this site. Got tv on floor, took back off, powered up and had four blinks. Checking the different circuits I have found for lack of a better term a phantom ground on p15v @ p11. With my oldest and most trusted Fluke I will see 800/900 ohms and ten minuets later 1.5k. Sometimes if I pull the p11 connector off the p board when showing a ground the ground will go away sometimes not. I can do the same thing with p2 going to the sc board, I will show a ground on p11, pull p2 off and ground is gone. Also I can power up with the ss disconnected and get four flashes and other times ten, and I will bounce between seven and and ten flashes with the sc disconnected and I do not want to start troubleshooting by throwing replacement boards at it. Thirty years industrial machinery repair with quite a bit of automation I would like to think I learned a thing or two about electronics but a tv is kicking my butt. Any help would be appreciated.
Hi all, I know this is an old thread but thought I would give it a try. Been going through all the different info posted here and I have a symptom not mentioned. A few days ago when shutting tv off heard a pop, tried to turn back on and no go, just blinking power light. I didn't know this thing had limited self diagnostics with the number of blinks. It must have started at ten blinks because I didn't notice any pattern to the blinks. Googled tc-p50g20 to see what info would come up and I found this site. Got tv on floor, took back off, powered up and had four blinks. Checking the different circuits I have found for lack of a better term a phantom ground on p15v @ p11. With my oldest and most trusted Fluke I will see 800/900 ohms and ten minuets later 1.5k. Sometimes if I pull the p11 connector off the p board when showing a ground the ground will go away sometimes not. I can do the same thing with p2 going to the sc board, I will show a ground on p11, pull p2 off and ground is gone. Also I can power up with the ss disconnected and get four flashes and other times ten, and I will bounce between seven and and ten flashes with the sc disconnected and I do not want to start troubleshooting by throwing replacement boards at it. Thirty years industrial machinery repair with quite a bit of automation I would like to think I learned a thing or two about electronics but a tv is kicking my butt. Any help would be appreciated.
You know if you read thr info you have presented you can deduce the SC is shorted . Often SC2 shorts or low resistance. The 15v line feeds the driver ic and also can go short if ic521 is bad enough. Send it to modus pts for rebuild. Q661 on thr SC will be a good one for a short check. Sure bet it's dead.
Yes you are correct q660 and 661 are shorted. I did read over my post and I guess I did answer my own question, I just have a bad habit of overthinking things. Well it's off for a rebuild. I thank you very much for your reply.
You know if you read thr info you have presented you can deduce the SC is shorted . Often SC2 shorts or low resistance. The 15v line feeds the driver ic and also can go short if ic521 is bad enough. Send it to modus pts for rebuild. Q661 on thr SC will be a good one for a short check. Sure bet it's dead.
Hello everyone, I also have a panasonic tc-p50g20. There was some flash of electricity and after this event the TV began to flash 10 shots. However, when I press the power button after the relay clique when reconnecting the TV, it flashes 4 shots. So I followed the troubleshooting guide for the 4 blinks. The last test gives 3.3 volts on pin 9 of connector P7. Subsequently, he tells me to change the P-Board.I would like some help in targeting the problem component on the P-Board. By the way, The VSUS and P15 is dead. By cons, I did the different test the Short for VSUS VDA and P15. No results below 1kohm.Thank you for your help.Jeff
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