Panasonic TC-P50S60 Plasma 7 Blinks

[kevinm34232]

I got this TV from someone who said it would not turn on, and had the 7 blink code. When I brought it home, it turned on and worked with no problems. I tested it for a while OK, and gave it to a friend.

A few days later the TV started the 7 blink code again. All signs pointed to the SC board. I replaced the board and the TV worked again. But it was still intermittent for a while, and now won't come on at all again.

I did the process of bypassing SD and SU, same 7 blinks. I have the normal 5V and 15V voltage on the SC that are part of the voltage check on startup..

The Vsus is where the problem seems to be. With the SC disconnected from the power supply, the Vsus comes up steady to around 208V. With the SC plugged in, it comes up to around 208V but fluctuates rapidly until the 7 blinks start (It only gives it a second or so for the test before shutting down).

I'm thinking maybe the power board Vsus is breaking down under load.. Any ideas on how I can troubleshoot this?? Thanks!

EDIT: Last pic, may be hard to see, but board is discolored from heat around Vsus circuit..

[ReeceyBurger123]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Seems like SC is shot again and is loading down the Psu. Have you checked the SC for short circuit ?

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

There is nothing obvious.. the test points in the TM that are checked:

Vsus to GND = 15.00M
VFO - VFG = 0L
F5V - VFG = 55k

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

I was hoping maybe a bad solder joint on the power board.. What's the likelihood of the SC board being intemittent initially (enough where the previous owner could not get it to work at all anymore), then it works fine for me for a while, then problem repeats.. And then repeats again after replacing SC board?? Does the heat damage on the PS board tell anything?

Attahced is underside of where board was discolored..

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

That really brown inductor leg looks really suspect. I'd cleaning that up desolder and apply fresh solder

[Alastair E]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

7-blink implies floating-supply issue--commonly associated with buffers.

Remove buffers, link SC50 and re-try. If set runs--buffers are faulty.

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Tried this.. No change when buffers are taken out of equation..

I reworked the solder joints around the areas of the power board that have over heated, and now I am only getting +-100V for Vsus, so something else has happened..

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

I am thinking it's the PSS. If the voltages going to the SC are erratic then the SOS circuits are going to trip once they're out of limits

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Woww this sucks.. I got a new/used SC and PSS board, same problem 7 blink instant shutdown with or without SU/SD bypass. The only way Vsus voltage will stay up is by removing the SC20 connector to the A board, and it holds about 10-12 seconds before giving 6 blink code..

Could this be a main board problem??

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Reading the SM again I see this, exact symptom to what I just posted above... Keeps pointing to SC board.. What's the odds the 3 of these are bad, and intermittent at times before??

Also there is no sticker that I can find on the panel (MC127FU6A11), where can I find the proper voltages to test? Not seeing in the SM or TM either..

Vsus = 207V
VFG = -195V
VAD = 200V
VFO = 148V

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Woww this sucks.. I got a new/used SC and PSS board, same problem 7 blink instant shutdown with or without SU/SD bypass. The only way Vsus voltage will stay up is by removing the SC20 connector to the A board, and it holds about 10-12 seconds before giving 6 blink code..

Could this be a main board problem??

It could but since you disconnected the SC20 and it stayed on for 11 secs and went 6 instead of 7 I think not.

2 SC boards both 7 blink with Sc50 jumpered, would think it points to SC but you said the volatages were erratic on Vsus . Is that the case or s it just the meter not refreshing quick enough?

Can you find any Transistors shorted on both SC boards?

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Vsus comes up then drops a little then stabilizes around 207V. This is a new/used PSS board too. Can you look at the voltages I just added above and see they look normal? I'm about to try disabling SOS7_SC2, I don't what else to try, unless all these SC boards have same problem... The first one I replaced when I first got it lasted a while, but it was even itermittent before that..

Also SOS7_SC2 is 0v without SC20 connected, 1.7V with it connected.

Im going to try 1 more SC board that is supposedly from a new TV damaged in shipping.

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Would you believe the mainboard on my washing machine just crapped, Mrs stomping, quick recap and working again.

Man can't get a moment to himself.

I'll have a read or actually I've got the back off a S30 so I'll grab some voltages.

what were you using for ground point? Chassis

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Vsus comes up then drops a little then stabilizes around 207V. This is a new/used PSS board too. Can you look at the voltages I just added above and see they look normal? I'm about to try disabling SOS7_SC2, I don't what else to try, unless all these SC boards have same problem... The first one I replaced when I first got it lasted a while, but it was even itermittent before that..

Also SOS7_SC2 is 0v without SC20 connected, 1.7V with it connected.

Im going to try 1 more SC board that is supposedly from a new TV damaged in shipping.

I've done something like that and got away with it and on other occasions burnt a PCB and destroy a complet set of Buffer boards so i would hang off on that idea.

Also i had a 4782 that I could not clear and earthed out the SOS 7 and it still shtdown. There may be a nother path.

Turned out part of the SOS cct was damaged on that but in the end I damaged it , too much tinkering to find the fault.

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Reading the SM again I see this, exact symptom to what I just posted above... Keeps pointing to SC board.. What's the odds the 3 of these are bad, and intermittent at times before??

Also there is no sticker that I can find on the panel (MC127FU6A11), where can I find the proper voltages to test? Not seeing in the SM or TM either..

Vsus = 207V
VFG = -195V
VAD = 200V
VFO = 148V

So you need to give me the gnd point s for each of these.

207V Vsus is not an issue, t's ball park

Vfg -195V with respect to what? On the 2011 set to gnd -160V

VAD if in respect to Vfg the I get about the same, to gnd 40V ( could be + or minus I forgot to check)

Vfo 148V, no idea and I'm not going to tr and find a test point for that one in case I short something out.

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

VAD and VFO I believe were floating ground, the rest to chasis ground.

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

VAD and VFO I believe were floating ground, the rest to chasis ground.

Then I don't see anything, don't think there's a lot of point measuring Vfg to chassis.

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

Would you believe the mainboard on my washing machine just crapped, Mrs stomping, quick recap and working again.

Man can't get a moment to himself.

I'll have a read or actually I've got the back off a S30 so I'll grab some voltages.

what were you using for ground point? Chassis

Did you say you had bad caps on the washer!?

[kevinm34232]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

So if another SC board does not work, are we just left with the A board at that point? Would removing SU/SD rule out the panel?

[tw2005]

Re: Panasonic TC-P50S60 Plasma 7 Blinks

So if another SC board does not work, are we just left with the A board at that point? Would removing SU/SD rule out the panel?

did'nt you say sc50 jumpered it fails too? That's with the SD/Su disconnected yes?

Just going through some other docs, all those volatages appear to be normal.

VAD - Vfg 200V
TPSC1 - Vfg 147V (Vfo)

F20V - Vfg 18.6V
F15V - Vfg 14.6V
F5V - Vfg , 5V