Hanns.G HL272 overheated SMPS

[patrikf]

Hi all!
I'm trying to fix a monitor that generally works, but has extremely low intensity backlight (on max setting it's extremely weak, in lower settings it flickers).
This monitor uses LED backlight.

Looking at the power supply, there is one obviously overheated component. There is also quite a lot of dried fluid type stuff in various places on the PCB (electrolyte?).

The overheated component is some kind of voltage regulator I think, labeled "S20N10". I'm sure there must be a less obscure equivalent somewhere, but I have not been able to successfully find any specifications on S20N10.

Anyhow, I suspect it overheated as a consequence of something else going bad. Prime suspect right now are the smoothing caps on the primary side of the transformer, as I can't see any smoothing going on there at all. (But SMPSs are a bit cryptic to me.)

I've got a few measurements and photos which I will post soon.

BTW, this same monitor has a thread here:
https://www.badcaps.net/forum/showthread.php?t=39618
but it looks like a different problem, and I didn't want to thread jack.

I appreciate any help I can get!

Cheers
Patrik

[Davi.p]

Re: Hanns.G HL272 overheated SMPS

"There is also quite a lot of dried fluid" please post picture of that.. can be normal glue..
"The overheated component is some kind of voltage regulator I think, labeled "S20N10" "
seems a marking of a double fast diode, if it is it can be normally hot, depends how much, how many seconds you can touch it? It's maybe possible of a too much high voltage due to bad caps or bad feedback.
"Prime suspect right now are the smoothing caps on the primary side of the transformer, as I can't see any smoothing going on there at all."
Can you explain this in other words? How do you see the smoothing, oscilloscope? Usually there's a 400v one and a 50v , which one you measured?
Bye.