LED TV power off

hard to know, but certainly failing caps are a common cause. One of those cheap chinese component testers is good for testing caps - the caps need removing to check them though.

NT

Dunno. I had a brand new telly wot done this. Took it back and got another

Yes when you say the original blew, exactly how did it blow? The reason I ask is that the behaviour you describe could just be a protection circuit doing tis job if something has caused a short somewhere. As has been said, you can try the capacitors. Samsung went through a phase a few years back when this seemingly was an issue. Brian

Yes switch mode psus can actually damage the semiconductors in the bit which is live to mains due to a mains spike, in which case it just is dead, but the one he has sounds more hopeful. Its probably quite old now though so he may or may not be lucky. Somebody in the old days would have been knowledgeable on such things, but these days particularly with the smaller sizes people tend to just dump them and buy a new one, sadly. Brian

I had to replace two obviously blown capacitors in my Samsung TV purchased in 2009, however they did last around 8 years.

The outward symptom was that the TV would not switch on reliably. I have a remote controlled mains plug and remove the mains from the TV and other under TV equipment each night after watching. On my TV a LED flashes during the power on sequence. This failed to flash occasionally when mains was re-applied. Cycling the mains on/off would allow a subsequent TV power on sequence to be successfully completed. Over a period of a month or so the times when the TV would not switch on became more frequent and sometimes more than one mains on/of cycle was required.

The two capacitors were in the power supply and had been positioned 1 mm away from a heat-sink. The top of both capacitors had bulged (domed).

The TV had a fan and although not providing an air flow to the power supply it had attracted all the dust in the world and required removing and cleaning.

To the OP. When replacing the capacitors buy replacements that are described as low ESR or low Z and are rated for 105C (105 degrees Centigrade) rather than anything rated at 85C.

Examples From Rapid Electonics

Many thanks - will get the board out later and give it a good inspection. I'm a firm supporter of fixing things rather than chucking them.

replace all 'lectros as a matter of course

That'll be a first, then. ;-)

As did mine. Just outside warranty.

Won't be buying another.

Not got an ESR meter, then?