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Question

LN-T5265F Power off and on

May 13, 2015 1:21AM PDT

So, thanks to you helpful folks, I have changed the capacitors out on the BN44 - 00150A power board twice. After each time, the TV worked for a couple of days then died again. The second time I changed the 13 electrolytic caps, I used higher voltage rated caps, but it turns out the caps never failed in my 7 year old set. After the second replacement, when the set died the 3rd time, I realized that maybe it was the days unplugged that might have fixed the problem. So, after it died the 3rd time, I removed AC power, let it sit for two days, and voila, the set worked when I plugged power back in. Any ideas what is failing and resets after no AC power for a while?

Discussion is locked

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Clarification Request
Did you try a new board?
May 13, 2015 1:32AM PDT

Why I ask is that the bad caps can strain the other components. Sometimes folk keep using the set (hey, it eventually stays on.) Not knowing the damage and strain the other parts are taking.

Only your less seasoned TV tech would replace caps more than once. My TV tech friends will change the caps once but on a call back will swap boards and crack the old board in two.
Bob

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Changed caps twice...
May 13, 2015 5:37AM PDT

Yes, I thought about changing the board, even ordered one, but after waiting a week the order came back canceled due to no stock at the supplier. I had read somewhere that the Samsung spec'd caps failed prematurely because they were spec'd with breakdown voltage too low, so I got some caps with a higher breakdown voltage.

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I wish that was true (ratings.)
May 13, 2015 5:43AM PDT

The sad story is more about corporate espinauge gone wrong. It's on the web. If it was a ratings issue, then makers would have been served up a much higher dose of court room visits. If you ever verify it's ratings, take it to a lawyer but in the decade or longer I've seen this across all makers (Dell alone get whacked with 2 million dead PCs) it's the same issue.

As to sources here it's shopjimmy and samsungparts.com
Bob

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Answer
maybe
May 13, 2015 3:26AM PDT
"o, after it died the 3rd time, I removed AC power, let it sit for two days, and voila, the set worked when I plugged power back in. Any ideas what is failing and resets after no AC power for a while?"

That's just how a PSU in a computer does, so you need to look to the power supply in it. When it overheats it will cutoff and some of them need to have power off, not just cool off, before they will run again. It's a deliberate protection mode in them.