PANASONIC TC-50PU54 Driving me crazy!!!

[Demonata08]

Been scratching my head for two days on this one. If anyone has any ideas. Im pretty new to repairing and electronics. Ive been doing fine with just soldering caps. But the caps dont seem to be bad on this one.

When it gets power you hear a pretty loud click(Which is apparently normal on this set) the power light comes on. holds for about 30 seconds then you can hear the power supply click as though it reset. It goes through this process several times. the power light normally stays on and you just hear clicking. Sometimes the panel will turn on. Its very rare but ive had it on for a few minutes at a time. When it goes off you see weird blocky lines right before it goes off. But it works fine, no lines, before that. Heres the reading on the pin out

|panel-ON: 0 | S1: 0 | S0: 0
|S054: 0 |STBY-ON: 28.7| STBY: 5
|F_STBY_ON: 3.2 |GND: 0 |GND: 0
|F15: 15.4 |F15: 15.4 |GND: 0
|15V: 1.3 | GND: 0 |15V: 1.3

The pin p2,p11(going to the other boards) are both 1.3v

I'm at the point of replacing a board because this seems like some sneaky problem. I just need to figure out which board is the problem.

Images
Power Board
Logic Board
SC Board
SS Board

[awyatt2]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

did you check the esr on the caps. looking only tells if they are bulging or leaking.could be a bad su or sd board. esr is important on these sets. I had one that looked perfect to the eye but three caps on the sc board were very high esr. had the same symptoms once in a while it would start and when it did the colors weren't right or it looked like a negative pic in spots.

[Demonata08]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

Sorry, As i said im kinda new to this stuff. I know esr testers can be used to test them on the board. but i dont have one of those. I desoldered all the caps from the power and tested the UF. they were all pretty close to the value labeled on the cap. is testing the esr different then testing the uf?

[awyatt2]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

yes, esr or equivalent series resistance is totally different from microfarads. if esr is high on a cap it wont work properly. you could replace the caps with a gen purpose cap and it probably isn't going to work at all, if it happens to it wont last long.. if I have a power supply that dosent have any visible damage I test the esr of the caps first.

[Demonata08]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

I gotcha. I just ordered me an ESR meter. Just curious. how do you know what ESR you need for the job? i dont see that labeled on the caps. Or is it just generally high esr is bad? if so what constitutes high? thanks a lot for the answers

[awyatt2]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

you will need to look at the specs on the cap or the chart that comes with the meter. it will vary on some but if it should be .5 esr and it goes to 1.5 then the esr is high. I bought a peak 70 a couple of yrs ago to replace a 60. the peak meters are high but I love mine.

[Demonata08]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

Does anyone happen to know if theres a way to get this model into self test mode? I know with samsung its shorting ps on to ground. But this one doesnt have volts on ps on unless its... On.. Lol. Cant find any info. Thanks in advance

[budwich]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

not sure what the list of voltages that you show are... at standby, at power up, at shutdown????

IF the list is displayed correctly, then the 15v pins don't appear to be happy at 1.3v. So what's up?

[Demonata08]

Re: PANASONIC TC-50PU54 Driving me crazy!!!

The voltages match what the pinout says they should when the panel is on. But it hardly stays on long enough to stabilize. It power cycles from on to standby every few seconds. But i know for sure its getting its 15v when it attempts to start.

Also checked every cap. The caps are all good esr and capacitance wise.