I have one of those va912b's with a bad power supply. I replaced 3 of the caps that were bulging, and when I plugged it pack in, I heard a pop (not an exploding cap) and nothing happened. Did I fry it with a bad joint or something? Or should I just replace the other caps too (except the big one).
Replaced bulging caps, and pop... nothing
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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.Comment
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Re: Replaced bulging caps, and pop... nothing
Definitely not.Comment
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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.Comment
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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.Comment
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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.--- begin sig file ---
If you are new to this forum, we can help a lot more if you please post clear focused pictures (max resolution 2000x2000 and 2MB) of your boards using the manage attachments button so they are hosted here. Information and picture clarity compositions should look like this post.
We respectfully ask that you make some time and effort to read some of the guides available for basic troubleshooting. After you have read through them, then ask clarification questions or report your findings.
Please do not post inline and offsite as they slow down the loading of pages.
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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.Comment
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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.Comment
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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 ???Comment
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Re: Replaced bulging caps, and pop... nothing
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.Comment
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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.Comment
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Re: Replaced bulging caps, and pop... nothing
IIRC, I believe that is a plastic cover. If you remove the screw, it should come off and expose the mosfet underneath.Comment
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Re: Replaced bulging caps, and pop... nothing
Data Sheet for the part is as follows:-
http://pdf1.alldatasheet.com/datashe...FSDM0565R.htmlComment
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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 aboveWhatever I do, I consider it a success, if in the end I am breathing, seeing, feeling and hearing!Comment
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