electronics (capacitors) question - samsung monitor

SqualidChimp

SqualidChimp

SqualidChimp

Associate
Joined
20 Oct 2002
Posts
610
Location
Glasgow
Although this is about a monitor, it isnt specifically a monitor issue, so I wanted to post it in General. Basically, if a capacitor looks ok, can it still be dud?

I'm trying to last-ditch effort fix my monitor (Samsung 2443BW) - just outside of the 3 year warranty period - which goes on for about 1 second then goes blank with a continuous audible high-pitched buzzing (similar to the buzzing that would last for about 1 or 2 seconds when the monitor was first powered on). If I was to compare it to a fluorescent strip light, it's perhaps like the noise just before the light comes on. For whatever reason the backlight isnt going on, and I can faintly see an unlit display if I try hard enough.

Having looked online, this would appear to be commonly caused by a dead capacitor(s). It sounded like it fit that profile, and so I took it apart to inspect the power board. Annoyingly, all of the capacitors appear ok - no bulges, burst or obvious leaks. I dont want to have to go to the trouble of replacing ALL of them on the hunch that one of them might be dead, since they all look ok. If I get any responses I will add in some pics - just wanted some generic advice. Or if you happen to have another theory of what might be wrong, it would be great to hear from you. :)

TY and inb4 "moving this to monitor forum"... that place is deadsville :D
 
Yeah they can look fine but still be dud, power it on with it in bits to see if you can figure out which one is buzzing, when you think you've found it remove it and turn it on again to see if the buzzing has stopped.
 
How long is it outside the warranty, had a Samsung 24" monitor was out by three months, contacted Samsung, it was collected & replaced foc.
 
@ Nightglow - my main problem is that I cannot find the original receipt with date of purchase. I contacted Samsung by phone last week, saying I thought it was just inside of or outside of the warranty period, and they said more or less, "Ah well, tough luck if you dont have your date of purchase or receipt."
 
I had a samsung monitor that just went it kind of flickered made a fizz noise and then went black I can still here sound, there were reports that Samsung new the capacitors were a proble and fixed it if was under warranty or not
 
 
Is it just the photo or in IMAG0045, the the middle cap in a row of 3 (C116 I think, off another pic, but it's blurry) looks a bit swollen?
 
 
Upon closer inspection... yes. I agree it looks like C111 has leaked. Never even noticed that wet bit - it showed up better in the photo than real life.
C116 looks to me just at flat on top as those around it (its the only one without what looks like a felt tip pen mark on it). I guess I have nothing to lose by attempting to replace them. :s
 
Caps don't always dome up on top when they leak. It depends on if there is an easier path for the fluid to get out. They also dry up giving no visible signs of deterioration, hence the ESR meters available.

There aren't many to replace so start with c111 and c116.

You can probably get all caps on eBay for a few quid.
 
I say replace all the caps beside the diodes, as tealc said you can get them at ebay for a few quid and they are probably faulty due to heat produced by the diodes besides them.
Caps does not like heat and it reduces its lifepan a lot.
 
Replace all the caps, they're very cheap to buy and super easy to replace. That's from somebody with the soldering skills of a 1 year old who managed to replace capacitors. :D
 
You must log in or register to reply here.
Back
Top Bottom