7 blinks of death for Panny Plasma TV, Viera, TC65PST34

[gundevar]

Hi All,

I am in need of help on "7 blinks of death" problem in Panasonic Plasma TV, Viera, Model # TC65PST34, TV was bought new in Year 2011.

This is what has happened so far in my efforts to figure it out:

- TV stopped working with a loud pop; No picture or sound after that.
- LED blinks 7 times in an infinite loop, which I identified as SC or SD/SU Board failure, according to Service Manual that I downloaded.
- I positioned TV on a table and removed the back panel.
- I bought the SC jig online and used it according to a Service Manual procedure to isolate SC board from SU/SD boards (Section 8.1 in Service Manual).
- After SC Board was isolated, SC jig inserted in SC50 port, and TV turned on, I continue to see 7 blinks, which Service Manual identifies as "LED blinking: Possible cause of failure is in SC board"

Please kindly advise what my next steps could be. Should I order a new SC board, or there is a way to get it repaired by someone?
I know that I still need to validate SU/SD boards. How can I do that?

I checked and I can buy all 3 boards online, but they are pricey. I am not a TV repairman. I have a multimeter.

SC Board to buy labeled as TNPA5399
Part Number TXNSC1NYUU
available on https://panasonic.encompass.com/item...1NYUU/Pc_Board
$239.80

SU board labeled as TNPA5346
Part Number TXNSU11TFU
$159.65

SD board labeled as TNPA5347
Part Number TXNSD1NYUU
$233.69

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Watch some videos on youtube on how to test SU/SD boards. Also remove the flat ribbon from the SC board and the power connector. Test for a short on SC board. There are videos on how to test the parts on the SC.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Thank you for the response and info, tvtimmy. I'll find and watch the youtube videos. In the mean time I ordered a SC board from

https://www.tvpartsnow.com
PANASONIC part number TXNSC1NTUU,
TNPA5399 Y-SUSTAIN BOARD

for $50. Has anyone had any experience buying parts from this shop? If yes, can you please share?

Thanks.

[tom66]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

I haven't...but I believe if you buy it via a credit card if worst comes to it you can do a chargeback.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Thanks, tom66.

Everyone, pls read my first two posts above in this thread and let me know if this is a valid plan going forward

1) get New SC board [already ordered]
2) replace the faulty SC board with the NEW one
3) while isolated from SU/SD boards, and using the SC jig, test the New SC board by powering the TV; If no blinks observed, I'll assume that New board is OK.
4) validate SU/SD [still need to learn the procedure]
5) upon validation in 4), hook up SU/SD boards to the SC board, then test the TV.

Can you advise about any intermediate steps that are missing, maybe some additional tests to actually see if the New SC board is good after Step 3) above?

Thanks,

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

That should be good. Look for a test point on each buffer board marked VGTP. Put meter in beep( short) mode and then put one probe on it and drag the other along each of the connectors for the panel ribbons. There are vids on this also. Makesure you save the old SC board for someone who wants to repair it.

[tw2005]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

That should be good. Look for a test point on each buffer board marked VGTP. Put meter in beep( short) mode and then put one probe on it and drag the other along each of the connectors for the panel ribbons. There are vids on this also. Makesure you save the old SC board for someone who wants to repair it.

Clean up any burn marks on the chassis, try and get the spring washer type bolts or make sure the old ones are firm, A simple diode mode check between the sd/su gnd plate and the output pins should be a good guide, nothing shorted = ok usually about a 0.7 reading depending on which way the probes are around,

If it changes from 7 to 8 blink then SS has a shorted transistor. Seen plenty of 50" models where it's taken an SC and SS repair to sort it.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Thank you , TVTIMMY, TW2005, for your responses.

This is my Summary so far and Next steps I'd like to have your kind feedback on:

Completed:

1) TV stopped working with a loud pop; No picture or sound after that.
2) LED blinks 7 times in an infinite loop, which I identified as SC or SD/SU Board failure, according to Service Manual.
3) After SC Board was isolated, SC jig inserted in SC50 port, and TV turned on, I continued to see 7 blinks, which Service Manual identifies as "LED blinking: Possible cause of failure is in SC board".
4) I ordered a New SC board; then replaced the faulty SC board with the NEW one.
5) While isolated from SU/SD boards, with SU/SD mounting screws removed, and using the SC jig, I tested the New SC board by powering the TV; no blinks were observed; the TV is on and hums a bit; no picture; a small LED in the left lower corner of the SC board is lit. My assumption is that the New SC board is working OK.

Next steps:

1) take out SD and SU board and test them using the procedure in this video: https://www.youtube.com/watch?v=k0EZHBr4dMQ
2) If test in 1) passes, reinstall SD/SU boards, hook them up to the SC board and test TV.

Question 1: do I need to take the SD and SU boards out before testing them?

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

You can test them in the set. Just flip up the locking clip to rake across the pins. If they are good, tv will work. Also, replace the screws with ones that have lock washers, or put a dab of locktite on the threads.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

You can test them in the set. Just flip up the locking clip to rake across the pins. If they are good, tv will work. Also, replace the screws with ones that have lock washers, or put a dab of locktite on the threads.

I am getting a lot of shorts, in both SU and SD, almost for every 3rd or 4th pin. What do I need to use for Ground? I currently use a spot where 4 screws are sitting that connect SU/SD with SC. I removed the screws before testing.
Just need to make sure I am checking for shorts the correct way.

I added a pic to show what I am using as Ground while testing pins on SU/SD. Please advice if this is a correct spot for Ground. Thanks.

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

That should work. Did you remove the su to sd ribbon connector? Check your screen very carefully for any cracks. I never had both buffers have shorts before.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

That should work. Did you remove the su to sd ribbon connector? Check your screen very carefully for any cracks. I never had both buffers have shorts before.

No, I did not remove the SU to SD ribbon connector before measuring resistance. Now I did, and got the same result: shorts in both SU and SD, all over. I just ordered new SD and SU boards [$62 for both], but now I feel less confident, since you told me that this situation with both boards being bad is rare. I cannot check screen for cracks now, because the TV is laying face down. I recall, there were no cracks when I put it on the table 5 days ago.

What else do I need to check before the SU/SD boards arrive?

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

There is nothing left to do but wait for new buffers to come in. Make sure you test them before you install them. Check that you have all parts hooked up and screwed down before you turn it on.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

There is nothing left to do but wait for new buffers to come in. Make sure you test them before you install them. Check that you have all parts hooked up and screwed down before you turn it on.

Will do. Thank you for your response, TVTIMMY, and all the good deeds you do in this Forum, helping folks like me.

Regards,
Gundevar.

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Keep us posted on the outcome.

[gundevar]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Success! Thanks a lot for all your help and advice, TVTIMMY, TW2005, TOM66!

It was a good learning experience. Vendor sent me a bad SD replacement board, I had to ask them to re-send. Also, I had really difficult time re-inserting 10 ribbon connectors into SD/SU boards, was finally able to insert it correctly.

Completed Steps:

1) TV stopped working with a loud pop; No picture or sound after that.
2) LED blinks 7 times in an infinite loop, which I identified as SC or SD/SU Board failure, according to Service Manual.
3) After SC Board was isolated, SC jig inserted in SC50 port, and TV turned on, I continued to see 7 blinks, which Service Manual identifies as "LED blinking: Possible cause of failure is in SC board".
4) I ordered a New SC board; then replaced the faulty SC board with the NEW one.
5) While isolated from SU/SD boards, with SU/SD mounting screws removed, and using the SC jig, I tested the New SC board by powering the TV; no blinks were observed; the TV is on and hums a bit; no picture; a small LED
in the left lower corner of the SC board is lit. My assumtion is that the New SC board is working ok.
6) take out SD and SU board and test them using the procedure in this video: https://www.youtube.com/watch?v=k0EZHBr4dMQ; both boards are found to have numerous shots
7) SD/SU boards are ordered at http://www.tvpartsnow.com/; Boards arrived and tested to be OK, no shorts;
8) New SD/SU boards are installed, hooked up to the New SC Board; I had hard time inserting 10 ribbons into SD/SU boards
9) the TV is working fine now.

[tom66]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Nice fix, glad you fixed it! These are great TVs, enjoy it, they do not make TVs as good as this nowadays.

[tvtimmy]

Re: 7 blinks of death for Panny Plasma TV, Viera, TC65PST34

Good job, glad we all could help!