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Comment by toast0 | Hacker News Reader

Samsung had a batch of these too; I suspect it's a combination of iffy suppliers and designing things exactly to the spec. Thermal design feels like it's often glossed over, especially with cables going everywhere and interrupting airflow.

On the other hand, if it's common knowledge that everyone overbuilds for tolerances on capacitors, it's easier to not feel bad about putting 95C electrolytic fluid in a can marked 105C if you "know" that it's common to bump up the rating by some factor when ordering parts.

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I just had my several year old Samsung 65" UHD TV fail from a bad power supply. I strongly encourage anyone able to use a screwdriver to look at the web before tossing a TV or committing to an expensive repair. My case appears to be typical. A couple dozen screws release the back. There is a power supply board somewhat larger than a piece of notebook paper, and two smaller boards which are the LCD drivers and the god awful 'smart' junk they made me buy to get a display. The power supply board is not made by Samsung, you can get a replacement for about $60US. Swapping it is just 6 screws and two easy release connectors.

I went in planning to replace capacitors, but none of mine had visible signs of damage and my board was showing thermal discoloring around other components, so I went with the new board.

Safety note: Turn the thing off, unplug it, and let it sit for hours before you go in. Probably longer than necessary, but I'm sure you have something else to do. These power supplies make >200V outputs for the LED backlights, on the "cold" side of the board isolated from the mains… so the cold side is packing more voltage than the hot side. Remember this if you are tempted to probe a live board.

WRT to the safety note, it's not as bad as CRT TVs where you had to worry about discharging voltages of 25 kV or so, but point taken.

The power supply on my TV died after about 5 years, but since it was an external brick it was trivial to cut the connector off and toss it on an old Dell laptop power supply (the TV wanted 20v, the Dell supply gave 19.5v, but it seems to work fine). I see now that official replacement power supplies are also available on Amazon for $16 if you don't want to hack together a replacement.

Update that no one will read: I went to recycle the old power supply board today and shocked myself twice, then I "petted" it with a strip of aluminum foil and got a really good CRACK out of one of the capacitor banks. So that's more than a week after it was unplugged. I thought those electrolytics would leak faster.

It was in fact a Samsung TV

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