Replaced bulging caps, and pop... nothing

[Karstedt]

Re: Replaced bulging caps, and pop... nothing

Thanks for the help guys, but that power switch proved a bit much for my amateur skills and underpowered iron. I mucked up a few solder pads when removing it, so I'm not really expecting it work when I patch it up.

[Rtech]

Re: Replaced bulging caps, and pop... nothing

That does not surprise me one little bit.

[alexanna]

Re: Replaced bulging caps, and pop... nothing

Used by some Acers,some Viewsonics and Hanns G HX191.....plus no doubt many others.

I have a Va912 here i just took apart but guess what---- has a delta board

[Rtech]

Re: Replaced bulging caps, and pop... nothing

Used by some Acers,some Viewsonics and Hanns G HX191.....plus no doubt many others.

[alexanna]

Re: Replaced bulging caps, and pop... nothing

https://www.badcaps.net/forum/showth...highlight=acer
looks like this acer uses the same p/s
wonder if samson still has to help identify parts?

Don't miss Rtechs post above

[Rtech]

Re: Replaced bulging caps, and pop... nothing

Data Sheet for the part is as follows:-
http://pdf1.alldatasheet.com/datashe...FSDM0565R.html

[Scenic]

Re: Replaced bulging caps, and pop... nothing

looks more like it has blown apart

your only chance would be to find the missing chunk with the part number on it..

[jetadm123]

Re: Replaced bulging caps, and pop... nothing

The fuse is definitely blown. But I don't know about what I'm assuming is the switching transistor you're talking about. It's definitely funny looking, but I don't know what it's supposed to look like. I can't read it either, so I don't what to replace it with.

IIRC, I believe that is a plastic cover. If you remove the screw, it should come off and expose the mosfet underneath.

[Karstedt]

Re: Replaced bulging caps, and pop... nothing

The fuse is definitely blown. But I don't know about what I'm assuming is the switching transistor you're talking about. It's definitely funny looking, but I don't know what it's supposed to look like. I can't read it either, so I don't what to replace it with.

[Rtech]

Re: Replaced bulging caps, and pop... nothing

Thanks,I know what Mosfets etc are, as I am electronics qualified,but you are the only one I have ever seen use the term on here,or anywhere else. You learn every day ....eh

[Trinite]

Re: Replaced bulging caps, and pop... nothing

Having worked with all sorts of electronics over many years...have never heard the term 'switcher' before.Terminology for many subjects can have different names for different things...so define 'switcher' in English please ???

The term "switcher" is short for "switching transistor". Essentially, it is a high power transistor (generally a MOSFET type, but also can be bi-polar) that is used in combination with a PWM (pulse-width modulation) circuit.

[Rtech]

Re: Replaced bulging caps, and pop... nothing

Having worked with all sorts of electronics over many years...have never heard the term 'switcher' before.Terminology for many subjects can have different names for different things...so define 'switcher' in English please ???

[Trinite]

Re: Replaced bulging caps, and pop... nothing

That switcher MOSFET looks a bit fishy to me. If you can get a close look at it, check for any pitting, cracks or discoloration. Also check the fuses (anything labeled with an "f" on the PCB) for continuity. An open fuse will indicate that it is more likely a silicon failure than a capacitor failure.

[mastertheknife]

Re: Replaced bulging caps, and pop... nothing

Also check this fuse, the live wire goes through this fuse before anything else.
Its probably blown, but without finding out the cause, it will probably blow again.

mastertheknife.

[Karstedt]

Re: Replaced bulging caps, and pop... nothing

I am not familiar with the "NTE" capacitors you used as replacements. What are their specs and how do they compare to the originals?

They are higher voltage with the same uF as the originals. I don't know the other specs, and haven't used them before either. They were available at the local electronics parts store, and they use them for repairing LCD's...

If you have no power and no power LED, then check the bridge rectifier (BD101) for shorts. Number the pins 1-4 and put your multimeter on 200 ohms.

With power off and lcd unplugged, measure pins 1-2, 1-3, 1-4, 2-3, 2-4, 3-4. Any reading under 30ohms suggests that the bridge rectifier may be shorted.

You are correct, no power, no LED. I'll check that this weekend. Thanks.

[retiredcaps]

Re: Replaced bulging caps, and pop... nothing

If you have no power and no power LED, then check the bridge rectifier (BD101) for shorts. Number the pins 1-4 and put your multimeter on 200 ohms.

With power off and lcd unplugged, measure pins 1-2, 1-3, 1-4, 2-3, 2-4, 3-4. Any reading under 30ohms suggests that the bridge rectifier may be shorted.

[yyonline]

Re: Replaced bulging caps, and pop... nothing

I'd expect that area of a power supply to use low ESR caps. I am not familiar with the "NTE" capacitors you used as replacements. What are their specs and how do they compare to the originals? They're not a brand I've heard of before, so I'm unsure of their long term reliability.

[Ritalin]

Re: Replaced bulging caps, and pop... nothing

Ya, I agree with replacing the others as well. Usually when they are in a cluster like that, they all get affected. You could take off the other ones and test them with a meter if you have one. Also check the bottoms of them for bulging, for some reason some brands tend to go bottom first then bulge at the top if it's that bad.

[Karstedt]

Re: Replaced bulging caps, and pop... nothing

Show us a picture of the switchers and the diodes. Those are the other things that tend to go "pop". Also a complete pic of the underside of the board would help too, as there are a lot of SMD components on that side.

Well, I can post some different angles and a complete underside. But I can't really get a much closer pic of anything... they get way out of focus.

Did you install one of the caps backwards?

Definitely not.

[retiredcaps]

Re: Replaced bulging caps, and pop... nothing

I heard a pop (not an exploding cap) and nothing happened.

Generally, when you see 3 bad caps, you might want to replace them all.

Did you install one of the caps backwards?