Panasonic TC-P50s2 7 blink problem

**Gies40** · 08-24-2013, 06:20 PM

Re: Panasonic TC-P50s2 7 blink problem

Originally posted by Gies40

Hi, this site is great, the help I see provided here is much more than I ever expected. Thanks for being here. I'm new to the thin TV repair work, including plasmas.

My tv shut down completely and I noticed on trying to restart that the indicator light blinked 7 times. I found on line that it was supposed to be the power supply board, bought a new one on-line, installed it but had the same problem. I disconnected the SS board and had the same 7 blink problem, re connected SS and disconnecting the SC board and saw the same 7 blink problem.

I'm currently only capable to service at the board level (not board components except maybe caps) but don't know where the problem is therefore which board(s) to replace. I have looked at the caps and found none that looked puffed up.

Any ideas on what the problem might be?

**tw2005** · 08-25-2013, 04:27 AM

Re: Panasonic TC-P50s2 7 blink problem

SC boards fail a bit on these but also could be SU, SD or worst case panel.

Could try this.

Remove the 4 VF_GND screws on the SU,SD boards

Unplug connectors SC41, SC46, and SC42 on the SC board.

Jumper pins 1 and 2 of connector SC50 on the SC board.

Then plug in the TV and turn it on.
Note: Do not allow the TV to stay on for more than 30 seconds

Is the TV still shutting down with 7 blinks?

No: faulty buffer boards ( TV will actually power up normally with no error blink if SC is good)

yes, Disconnect SC20. Plug in the TV and turn it on

Did the number of blinks change to 6 blinks?

Yes : faulty SC
No: A board

If SC is faulty, good practice to also check buffer board resistance as they too could be faulty or shorted.

The steps above I copied from a flow chart.

**Gies40** · 08-25-2013, 09:31 AM

Re: Panasonic TC-P50s2 7 blink problem

Thanks tw2005, I'll try it as you say.

**Gies40** · 08-27-2013, 07:08 AM

Re: Panasonic TC-P50s2 7 blink problem

I ended up with 6 blinks after disconnecting SC20 so based on the flow chart you referenced I have a faulty SC board.

You also said to check the resistance of the buffer boards.
Considering that I'm new at this how exactly would one do that?

Thanks in advance.

**tw2005** · 08-27-2013, 07:21 AM

Re: Panasonic TC-P50s2 7 blink problem

So I take it with the jumper at SC50 you still had 7 blinks then?

**tw2005** · 08-27-2013, 07:35 AM

Re: Panasonic TC-P50s2 7 blink problem

see if you can make sense of post 58

https://www.badcaps.net/forum/showth...t=26322&page=3

you have same buffers as mine except i believe you have no heatsinks.

I'd measure in both polarities with the probes and see if they get close, meter will need to be able to read 5-6 M ohms although as long as it can read to 2 Mohms that should give a reasonable idea.

Don't want greatly lower or shorted. Gnd to all buffer output pins should show nothing in diode test from memory.

If you feel like it , on the SC measure resistance across SC2, and the P5V , P15V in relative to gnd at SC20.

Download the service manual for guidance where those points.

List the readings for everything you get.

This one has 10 blink, also bad SC and buffers appear to be bad too from what's been said.

https://www.badcaps.net/forum/showthread.php?t=30375

**Gies40** · 08-27-2013, 07:38 AM

Re: Panasonic TC-P50s2 7 blink problem

Yes, 7 blinks with SC50 jumped.

O.K., I'll take a look as you suggest.

Thanks,

**tw2005** · 08-27-2013, 07:40 AM

Re: Panasonic TC-P50s2 7 blink problem

Did a few edits , not sure if you saw everything.

**tw2005** · 08-27-2013, 07:45 AM

Re: Panasonic TC-P50s2 7 blink problem

Another 10 blinker, but SC reported bad too.

https://www.badcaps.net/forum/showth...light=tc-p50s2

**Gies40** · 08-27-2013, 09:16 AM

Re: Panasonic TC-P50s2 7 blink problem

Yes, thanks TW, getting the service manual now and looking for my multimeter - I haven't used it for a few months.

**Gies40** · 08-27-2013, 01:24 PM

Re: Panasonic TC-P50s2 7 blink problem

TW, I'm having trouble finding the test pads on the boards. I did go to the service manual SC boards layouts but didn't find "VFO", "VSCN-F" (I did find VSCN but no "F" with it. ), the "5V_F" etc., from your charts. I guess that could be just any 5V test pad?

I can measure them if I can find them but so far, no luck. Is there a place that explains the codes?

Thanks again,

**tw2005** · 08-27-2013, 01:43 PM

Re: Panasonic TC-P50s2 7 blink problem

Originally posted by Gies40

TW, I'm having trouble finding the test pads on the boards. I did go to the service manual SC boards layouts but didn't find "VFO", "VSCN-F" (I did find VSCN but no "F" with it. ), the "5V_F" etc., from your charts. I guess that could be just any 5V test pad?

I can measure them if I can find them but so far, no luck. Is there a place that explains the codes?

Thanks again,

The SD and SU buffer boards are what you're testing next.

Try the block diagram 4/4 maybe and connectors are SU41 SD42 on the buffer boards.

all you have to do is find the connector (there's only 3 between SC,SD,SU), identify which pins are 1,2,3 ...etc..9, measure between the gnd plate and each pin as I have in that post and write it down.

Boards disconnected from SC, and disconnect the little ribbon between.

see how you go with that.

**Gies40** · 08-27-2013, 01:53 PM

Re: Panasonic TC-P50s2 7 blink problem

Yes, I see that we're testing the SD and SU boards but the terms under the "SD42" column in the chart confused me.

So am I to understand that the terms under SD42 in your chart are the names of those pins, not some test pad that I bridge to? O.K., if that's it I'll go right to it. I'm just a little slow getting up to speed. Thanks,

**tw2005** · 08-27-2013, 01:57 PM

Re: Panasonic TC-P50s2 7 blink problem

Yeah, if you find that block diag, that's where I got the labels from, find the pins 1 -9 and measure to gnd. I don't understand fully those labels either, that's just what they have called them.

**Gies40** · 08-27-2013, 07:12 PM

Re: Panasonic TC-P50s2 7 blink problem

Should the 4 VF_GND screws and the SC20 ribbon cable to the A board be reinstalled and the jumper be removed prior to measuring the resistance? In other words the only thing disconnected would be SC 41, 42 and 46 and use those GND screws as ground?

**tw2005** · 08-28-2013, 03:08 AM

Re: Panasonic TC-P50s2 7 blink problem

I'd normally take the boards out and do it but should be able to get an idea at the connectors but you won't be able to test the output to gnd if the panel is connected to it.

**Gies40** · 08-28-2013, 10:00 AM

Re: Panasonic TC-P50s2 7 blink problem

I removed the SU and SD boards and measured the pins with both polarities.
I thought I got some crazy readings like 38M on some pins under one polarity measurement but when switching they were more reasonable.
The results follow:
SD Board:
+ Polarity - polarity Target
pin # 1 6.49M 30M 1.86M
#2 218K 218K 220K
#3 OL
#4 Ol
#5 38M 6.6M 5.3M
#6 38M 6.6M 5.1M
#7 OL
#8 38M 1.14M 5M
#9 OL

SU Board:
+ Polarity - polarity Target
#1 OL
#2 6.36M 26M 1.9M
#3 OL
#4 218K 218K 220K
#5 OL
#6 OL
#7 Ol
#8 38M 7.7M 6.3M
#9 OL

I don't know how far off the resistance needs to be to cause a failure but pins 2, 5,6 and 8 on the SD seem to be out of range too far as do pins 2 and 8 on the SU. My inexperienced judgment would say that SC, SU and SD boards need to be replaced. Would the bad SD and SU boards make the SC board look bad while it may be functioning properly or is it good judgment to replace all three. Comments please.

**tw2005** · 08-28-2013, 02:58 PM

Re: Panasonic TC-P50s2 7 blink problem

Originally posted by Gies40

I removed the SU and SD boards and measured the pins with both polarities.
I thought I got some crazy readings like 38M on some pins under one polarity measurement but when switching they were more reasonable.
The results follow:
SD Board:
+ Polarity - polarity Target
pin # 1 6.49M 30M 1.86M
#2 218K 218K 220K
#3 OL
#4 Ol
#5 38M 6.6M 5.3M
#6 38M 6.6M 5.1M
#7 OL
#8 38M 1.14M 5M
#9 OL

SU Board:
+ Polarity - polarity Target
#1 OL
#2 6.36M 26M 1.9M
#3 OL
#4 218K 218K 220K
#5 OL
#6 OL
#7 Ol
#8 38M 7.7M 6.3M
#9 OL

I don't know how far off the resistance needs to be to cause a failure but pins 2, 5,6 and 8 on the SD seem to be out of range too far as do pins 2 and 8 on the SU. My inexperienced judgment would say that SC, SU and SD boards need to be replaced. Would the bad SD and SU boards make the SC board look bad while it may be functioning properly or is it good judgment to replace all three. Comments please.

I would say they're ok, nothing obviously shorted and the results from each board are similar. Can't explain why, but the ones in bold are what they get you to test in the training guide.

I would give them a go again, finding a SC will be the hard part for this,

How did you go with the SC board at the SC2(Vsus), 5v & 15V lines

**Gies40** · 08-28-2013, 04:37 PM

Re: Panasonic TC-P50s2 7 blink problem

O.K. Yes, getting the SC board doesn't look good. I tried shopjimmy but it's out of stock.

I'm sure Panasonic's $$ would be much higher. Any other ideas?

I didn't get to the SC board test yet. That's the plan for tomorrow. If that tests fine where do we go from there? The screen itself?

What's the training guide?

Panasonic TC-P50s2 7 blink problem

Panasonic TC-P50s2 7 blink problem

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