Diodes in SEG LED TV

[Nick]

Although I have been repairing/restoring/renovating vintage equipment for more years than I care to remember, I am very new to solid state work and fairly clueless!
My flat screen TV has been in for repair on a previous occasion and has failed again in the same manner, totally dead. Opening it up I find a clearly fried diode, and a previous botched looking repair to a couple of nearby diodes.
From the picyures provided, could anyone please enlighten me as to suitable replacement diodes for D11, D14 and D15 please? I will be at Golborne on Sunday if it would help to see the board 'in the flesh'.

The PSU is an LK-PL260205B as used in many TVs - they are available for very little (not much more than a few diodes!)

e.g. https://www.vareza-elektronik.de/product...ts_id=6911

Looking at the photo of the "good" board from the above site, that 3rd "bridging" diode between D14 & D15 on your board is not there. Before just replacing stuff that looks dead, perhaps ask yourself why it died in the first place...

[Crackle]

The D11 on that board for sale does not look all that healthy either, yet they claim it is "PART HAS BEEN REMOVED FROM A WORKING ,DAMAGE SCREEN TV, PART IS TESTED AND IS IN FULLY WORKING ORDER."
   

Mike

[Nick]

The D11 on that board for sale does not look all that healthy either, yet they claim it is "PART HAS BEEN REMOVED FROM A WORKING ,DAMAGE SCREEN TV, PART IS TESTED AND IS IN FULLY WORKING ORDER."

Not sure it's a problem - all the photos of that board that I've seen have green gunk on D11, e.g.

https://spares2repair.co.uk/unknown-manu...4001011196

...and, for that matter, the OP's photos...

EDIT: Actually, it looks like there's a ferrite bead on each end of the diode, and the gel/glue is there to stop them rattling around and to keep them in place...

[Murphyv310]

I'd be more worried about the CapXon capacitors.

[Nick]

I'd be more worried about the CapXon capacitors.

Yep - those too. Definitely a "built to a price" PSU... unless the tops are bulging, they may be OK...

...but if you need to replace all those, for the price you could get a "known good" unit...

[Crackle]

So maybe the diode in Geoff's photo is not fried after all.

Mike

[Murphy Maniac]

Returned from Golborne armed with suitable Schottky Diodes, kindly supplied by Keith, and had another good look around following your comments. Looking more carefully under a magnifying glass, D11 has indeed got ferrite beads on each end held together with green gunk, tests OK as well. I intend to replace it anyway and hope for the best. As you so rightly point out, the boards are cheap enough to replace en bloc rather than messing about testing and replacing all those dodgy foreign electrolytics.
Many thanks for all your helpful advice, I will post the result when I get the replacement diode for D11.
Best Wishes to all,
Geoff.

[Murphyv310]

Hi.
CapXon were sold either by SEME or Charles Hyde, I can't remember which one, we bought them a few times latterly in the business. We found that we were getting failures after six months. Eventually we started checking the new ones and found their ESR was poor. Switching to a different make stopped the issue and the repeat calls.