is this a bulging capacitor? audio receiver suddenly not working.

H

hardboner

Limp Gawd
Joined
Feb 23, 2016
Messages
235
Are all big caps made with flat tops?

check mine out... Dunno if these two big caps are the cause of my harman kardon receiver not working all of a sudden...

IFMoIUG.jpg
 
Better question.. what's not working? Is it powering on with no audio or no power at all?
 
it powers on. But right before the sound died, there was a lot of static and loud noise.

no audio anymore
 
In that case I wouldn't be looking towards the capacitors. Maybe an inline fuse, or more likely, a relay issue. When you turn it on you should hear a relay click for power and then one initializing the output.
 
Your manual will give you a more detailed relay engagement than I can, though. Being different from mine (Yamaha) you may actually have a different start expectation from them.

Side note: try some headphones and see if you can hear the audio.
 
The bulging capacitor thing was a one off occurrence was it not? Wasn't that related to counterfeit capacitors being made in china and imported... i don't think it's a regular occurrence.



THAT SAID, they could be bad, you need equipment to test them. Yes, it could cause your receiver to go all sorts of crazy.
 
Doesn't sound like caps. But that left one looks a bit suss, crease along the top could be the scores (to blow) coming through.
 
While yes , the capacitor plague was a one off occurrence , they fucking made billions of those damn things.
I just fixed a TV last week with those stupid caps.
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I agree , the left one looks bad.Try and peel the plastic top bit off.
 
Those are definitely bulging capacitors. Might not be your only issue, but those capacitors have got to go.
 
auntjemima said:
In that case I wouldn't be looking towards the capacitors. Maybe an inline fuse, or more likely, a relay issue. When you turn it on you should hear a relay click for power and then one initializing the output.
Click to expand...

yeah, i hear a click when powering on, and the front lcd lights up.

So, what happens if I can hear audio in headphones? what would that rule out?



As for the big caps, they're hong kong Koshin brand caps.

This is a harman kardon 3480 receiver
 
If you hear the audio in headphones, it would suggest the pre-amp stage is fine.
I thing the part that dies most often in these devices are the power amplifier transistors. There should be like 2 of them for each channell, they look like regular transistors but quite bulky and usually connected to a radiator.
Those caps do look a bit suspicious, especially the one further in the photo. But, I also have big caps in my output stage and they too are not perfectly flat-topped, even though they are perfectly fine.
You should still be getting some sound even if they fail. Transistors - not so much.
 
Exactly. The caps looks pretty much like the ones I have. The tops in those are bulged at all, if anything they look uniform and completely normal. Not all caps have a completely flat top. Judging by the side condition they seem completely normal.

Checking transistors, as they are not always obviously damaged, would need an incircuit tester or a way to remove them and test them.
 
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