JUMP TO SOLUTION Solved

Original topic:

UN55MU8000 turning on and off, no image, red light flashes once with each power up/down

(Topic created: 09-27-2020 08:48 AM)
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

Howdy all, As stated my tv suddenly went black while watching it last night. The power, unless unplugged, continually turns the tv on and then off. There is no image, I can just see that the screen is powered up. It then turns itself off. rinse repeat. When it initially happened we could still hear sound. Now there is nothing. I cold booted the tv and checked all source cables and peripherals. I am guessing it is a power supply or control board issue. Any pointers on how to troubleshoot these? The TV is a 2017 model.

Thanks.

 

Edit:  I recieved several phone calls regarding this and was transferred several times. They told me they couldn't find anyone to service it and just canceled the ticket. I do this kind of work and sell and service appliances. I said that if they just send me the parts, I would take care of it and we could call it square. I sat on hold for almost an hour and then recieved an email saying the ticket was canceled. The last person I spoke with said the TV had been out of warranty for several years. The TV is only 2 years old. So thats not possible. I am becoming increasingly u happy with the service and I usually rave about Samsung. Everything electronic I own is samsung. Am I out of luck here? 

14 Replies
SamsungTam
Samsung Moderator
Samsung Moderator
Options
4k, 8k and Other TVs

How long does it stay on before turning off again? Is it possible to check the current software on tv?


Be sure to click " ✓ Accept as Solution" when you find an answer that works for you.

0 Likes
Reply
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

1-3 seconds. The screen stays black but you can see that it is lit.  the tv was connected to wifi and would usually update software automatically but I cant currently access that information.

0 Likes
Reply
SamsungTam
Samsung Moderator
Samsung Moderator
Options
4k, 8k and Other TVs

How long have you had the unit?


Be sure to click " ✓ Accept as Solution" when you find an answer that works for you.

0 Likes
Reply
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

bought it brand new November 2017

0 Likes
Reply
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

bought it brand new November 2017

 

edit: Sorry, I dont know how that managed to post twice

0 Likes
Reply
SamsungTam
Samsung Moderator
Samsung Moderator
Options
4k, 8k and Other TVs

Can you send me a private message with your full model and serial number? http://bit.ly/2tCGnGK


Be sure to click " ✓ Accept as Solution" when you find an answer that works for you.

0 Likes
Reply
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

sent. Thank you.

0 Likes
Reply
GrottyKnight
Asteroid
Options
4k, 8k and Other TVs

 I recieved several phone calls regarding this and was transferred several times. They told me they couldn't find anyone to service it and just canceled the ticket. I do this kind of work and sell and service appliances. I said that if they just send me the parts, I would take care of it and we could call it square. I sat on hold for almost an hour and then recieved an email saying the ticket was canceled. The last person I spoke with said the TV had been out of warranty for several years. The TV is only 2 years old. So thats not possible. I am becoming increasingly u happy with the service and I usually rave about Samsung. Everything electronic I own is samsung. Am I out of luck here? 

0 Likes
Reply
Crim91
Asteroid
Options
4k, 8k and Other TVs

It's a very common issue for the 8-series. Same thing happened to mine, for the most part.

Pictured faded to a saturated green color before the TV shut off. After that, I tried turning it on again and it would consistently power-cycle as you describe.

Aside from all the pointless troubleshooting steps they tell you to perform, I've removed the back panel, inspected all cables, connectors, and the boards themselves. I even inspected the components under a thermal imaging camera to see if there were any obvious excessive heat spots on any components. I also removed the heat sink from the CPU on the logic board, cleaned and reapplied thermal paste, then re-fastened it.

Nothing fixes this issue.

The only difference I could make was when I removed the ribbon cables from the logic board coming from the power board. This would result in the backlight coming on and staying on, but would obviously produce no picture or give any functionality. This leads me to believe it might be an issue with the logic board.

I've heard from others that replacing the logic board only seems to be a temporary fix, as it seems there might be a "timing" issue between the boards and the panel itself, but I haven't found much else on that possibility.

Samsung refuses to put me in touch with a technician; these support mods aren't helpful at all.

0 Likes
Reply