Capicitor Help

[dexterous]

Sorry to ask a question for my first post. I have a Conexant Router and it has a capacitor that is making a squealing sound and is driving me mad.

Can anyone identify this capicitor for me so I can replace it.


Any help would be appreciated.

[Dazza]

Hi dexterous, and welcome :D.

Could this component be a "choke" have a look if you can, at the leads between the component and the PCB, are the leads enamel copper wire?  Even if the leads are not enamel copper wire, it could still be a choke.

[prateeksikka]

hi there!
you must also check for the surges in the supply current for the capacitor.
Varying currents produce the magnetic field and thus electromagnetic waves produce the sound.
this could solve the problem.dont forget 90% of electronic bugs are in the power supplies. :)
prateek

[steven]

:) it looks abit like an inductor to me as the grey looking cover is like the ones on my inductors. hold a magnet to it and if it sticks, then you have an iron core inside that, and it would be an inductor , if it dosent stick it would be a capacitor , but unusual one for what i can see

[Dazza]

Hi steven :),

Of course, use a magnet to see if it's an inductor, now why didn't I think of that ::).

[audioguru]

It was hard to get to the pic, but the pcb seems labeled "L25" above it. "L" usually indicates an inductor. If it has a ferrite core then a magnet will ignore it. ;D 

[steven]

some of my inductors ive dismantled and there like a wheel with an iron shaft and at each end there is a disk or barrel shaped and there magnetic, i kept them in case i devle into the perpetual motion machine stuff

[dexterous]

Thanks for your replys

A magnet will stick to it :)

And when you put the magnet near it while its on.. it will go louder.. The noise also makes my speakers produce a similar sound.

I have also tested the voltage on the power supply, it seemed to be at around 32v, when I tested it while it was plugged into the router the voltage changed every so often, when the squealing stopped the voltage went upto 31.05 when it squealed again it went down to around 30.50? What could be at fault?