Sony OLED XR-77A80J - 5 Flashes But Turn On After Hard Reset

[Davi.p]

You are right with doubt on power board, if 1²v (sorry, my phone screen keyboard is getting mad) or ²4v are low then tcon does not start well and tells the MB it hàs à problem, but your action of buying à power board is so rookiē, power boards càn be easily tested on bench, and tcon? have you followed my purchàse advices? For the tcon doubts i understand but i only pàrtiàlly agree.. i will explain in future..

[odie34]

Davi.p Both the T-Con and power board are returnable. I could see trying to fix the original power board if it turns out that that’s the problem, although in that case I’d probably sell the one I bought rather than returning it. (It doesn’t seem right to return a part that aided in the repair… and I got a good deal on it.) The bottom line is that I was running out of patience and needed to be able to definitively rule some things out.

[Davi.p]

Try a first step with simple hair dryer at max temp, this is not a reflow obviously but we don't need it i think..

[odie34]

I received the replacement power board and T-Con today. I installed them one-at-a-time, but the problem still remains… The TV turned on and acted fine, but then shut down a few seconds later. At this point the only things left are the main board and the panel. The panel seems more likely given the other tests we’ve done, although the screen looks perfect for the few seconds while the TV is on. I suppose it could be a problem with the LVDS cable, but how often does that happen? Any suggestions?

[Davi.p]

5 flashes seems panel at this point but try at power off with hairdryer on the MB processor, then turn it on, if the defect varies bad processor soldering, try also to Ram/Rom..

[odie34]

I know that you can remove one of the two cables between the T-Con and the panel on standard (non-OLED) TVs to help identify where a short is in the panel. Can you do the same thing with OLEDs or might that damage something? (It would be a pretty definitive test if the TV stayed on when connected to one side but not the other.)

[Davi.p]

you can do it

[odie34]

Sorry that it's taken so long, but I wanted give a quick update to everyone who has helped me through this process... Unfortunately it turns out that the problem was a bad panel. Over the course of my tests and board swaps I was finally able to get definitive proof, which can be seen about 12 seconds into the video at https://youtu.be/HD1rEY37GRY

You can see a thin black line about 10% down from the top of the screen. Very disappointing, but it was fun working on it and I really wanted to thank you all for your help. Hopefully I'll have better luck next time.

[Diah]

Sorry that it's taken so long, but I wanted give a quick update to everyone who has helped me through this process... Unfortunately it turns out that the problem was a bad panel. Over the course of my tests and board swaps I was finally able to get definitive proof, which can be seen about 12 seconds into the video at https://youtu.be/HD1rEY37GRY

You can see a thin black line about 10% down from the top of the screen. Very disappointing, but it was fun working on it and I really wanted to thank you all for your help. Hopefully I'll have better luck next time.

still yours OLED usable, don't trash it, try to isolated the error sos signal rail... or add load like lamp to the EVDD line to handle and take any over load current so the the SOS will not trick on..

[odie34]

Darn! I didn't realize that that was a possibility. I thought that there was nothing to do if there was a short in the screen so I recycled it. Next time...

[EazyBone]

The boards were worth like $200-300 on eBay also

[odie34]

I still have the boards. I'll list them when I have time...

[Davi.p]

it could have tried something to save it, if you are in time tell me..

[odie34]

Sorry.. it's already gone, but I'll know for next time. Thanks for all of your help.