Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

[VikramB]

First thread here on this forum, excuse me if I miss something in my first post.

I have the 55” variant of the Frame TV which is essentially a QLED tv. There's a weird problem where it would keep on restarting on its own. Funny thing is it might work perfectly for couple of days and then decides to go down the restart route. A few pointers:
1. If I let the TV sit idle for a day, for the very first time it boots after that time period it usually keeps working for 5 minutes before restarting. After that it restarts every 5 seconds.
2. I've tried the tape method and seem to find a pin where I can see the picture (although with frame skips, vertical lines and what not) and the TV doesn't restart. It's the VGHD panel pin.
3. Since I've tried the tape method, that also implies I've eliminated other potential causes. Basically if I remove the display connector, there's sound and no restarting.
4. If the panel is faulty, why don't I see any dead pixels or horizontal/vertical lines when the TV is working properly?

I do have the service manual with me but not able to decode which pins should I try masking for a stable picture. I don't mind even if I end up with a dead pixel row. Any sort of help would be appreciated.

[nomoresonys]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Guess it depends on where the short is, here's a good video: https://www.youtube.com/watch?v=pfrRhw7-ZII

[VikramB]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Guess it depends on where the short is, here's a good video: https://www.youtube.com/watch?v=pfrRhw7-ZII

Thanks for the prompt response. As a matter of fact, I saw the exact same video before going ahead with the tape fix. Unfortunately this particular model doesn't have an isolated TCON board. Also, the COF strip has a connection for the right part of the screen, but the left part is soldered. I've tried disconnecting the right side and it still restarts. Can't check the left part though

Now, coming to what's shown in the video, I've actually tried taping those CLK pins but I end up creating more mess. Instead of any improvement the image deteriorates further. The best I could do was by masking only the VGHD pin. I guess I'll have to check for shorts on the driver.

[nomoresonys]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Good idea, some have been having various luck by removing diode packs and or resistors on the panel driver boards.

[VikramB]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

One thing I’m still not sure about is the varying time between restarts. A short, if it’s there somewhere, is a SHORT after all. It shouldn’t be unpredictable. For instance the TV is running fine for the last 2 hours, making me scratch my head even further.

[nomoresonys]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Howardc64 just had good luck removing resistors on his LG: https://www.badcaps.net/forum/showthread.php?t=116761

[nomoresonys]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

One thing I'm still not sure about is the varying time between restarts. A short, if it's there somewhere, is a SHORT after all. It shouldn't be unpredictable. For instance the TV is running fine for the last 2 hours, making me scratch my head even further.

Yes, that is a very good question, the first thing I always think when the shutdowns are random is a bad/weak capacitor or an iffy solder joint.

[VikramB]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Aah right the caps. Even a weak solder joint too could be the culprit. I guess I’ll just seek some professional help. Samsung quoted me an insane amount for the panel. They don’t do repairs anymore. Instead they just change the complete part.

[VikramB]

Re: Samsung QN55LS03 | The Frame TV | Weird power cycle and restart problem

Update: Got a professional to look into the issue. A panel COF is the culprit. Will probably have to get the whole panel replaced since the part is not available here.