humming noise in headphones even when cpu is off

[saadminhas]

i am experiencing a weird humming noise in my headphones. the problem persist even when my pc is turned off. when i touch any metal part of the casing the humming stops.i disconnected the power supply cable still there was this humming noise so i disconnect my vga cable aswell and the sound stops. only when the metal part of cpu or my monitor screen when comes into contact with any part of my body the humming stop. can anyone please help be out ?

 

[Demosthenest]

sounds like some weird vibration. I don't think there's much you can do. Maybe connect the headphones to an other jack?

 

[Xavier Bouttier]

This is 100% static electricity, hence the 'static noise' you hear on your headphones. Make sure your headphone cable isnt too close to any other cable. Audio cables are generally not shielded, so can pickup electrical interference from other sources.

Either re-arrange the cables so the headphone cable isn't too close to other cables, or buy better headphones.

They still hum when the PC is off, because of residual static electricity.

 

[saadminhas]

i already tried connecting to another jack it didnt help. headphones are fine when i connect it to other devices. is there nothing i can do to fix this issue ?

 

[saadminhas]

and how come the humming stops when i touch the cpu or my monitor screen ?

 

[Demosthenest]

I guess because your body absorbs the static electricity. I'm not an expert in the subject, Xavier could help you better.

 

[saadminhas]

Thanks for replying. Xavier if you know about any possible solution please let me know i would really appreciate it.

 

[Xavier Bouttier]

and how come the humming stops when i touch the cpu or my monitor screen ?

This proves that it is static electricity. Your case is grounded, and so is the screen (via the wall socket of your house), and any residual static electricity in your body and headphones, will dissipate through your hand, into the case/or screen (metallic parts) through your wall, and into the ground.

Do you have carpets? Is it generally very dry in the room? all these factors play a roll in static electricity. Ultimately, as a ghetto fix, what i can think of at this point, would be to have a static bracelet attached to you and grounded.

 

[saadminhas]

i dont have carpets in my room and the room is morderately dry not very dry. would changing the surface on which my cpu and monitor sits will make any diffrence. the current surface is wooden table covered with formica sheet

 

[Xavier Bouttier]

I dont know about the pc case and monitor, since evidence points to the static building up in your body and headphones, and not the case and monitor

 

[saadminhas]

ok so i solved the problem. the trick was to change the outlit in which the 3 pin plug of power supply was going in . it was not getting grounded properly. taking the pluge out completly did not solve the issue as the pluge needs to be grounded properly to get rid of the static electricity. Tanks for all the positive replys anway. i hope this post will help others to resolve similer issues.

 

[Xavier Bouttier]

Glad to hear you fixed the problem mate.

 

[bgh928]

it is maybe because the audio output and USB port is sharing same ground. This can be resolved if you could separate USB and audio ground but this requires soldering skill.