Solved Weird sound like static from PSU

Ok so the psu was perfectly running without any noise until i switched the motherboard to an ATX from mATX AND adeed 4gb ram (total 8gb ram). And now its making this weird noise like a static. even when the pc is in idle.
Video: https://photos.app.goo.gl/yhqqputHHawum8KH7
PC SPECS:
CPU: Intel Core 2 Quad Q6700 2,67GHZ
GPU: AMD RADEON HD 8570 2GB DDR3
HDD: WD BLUE 1TB 7200RPM
PSU: 400W NO NAME BRAND
RAM: 4X 2GB 800MHZ takeMS

No such sound in the headphones.
EDIT: When cpu and GPU are at full load ( I was playing GTA v ) the sound stops but I don't know exactly for how long. Maybe is it because they start heating.

Bruce said:

and it's coming from out of the PSU, not the speakers?
have you tried hitting it with some air - from an air-compressor or compressed air can?

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Not the speakers. Just from inside or outside near PSU. Haven't tried to use air compressor. I'll try and come with an update

Ok

vger said:

If you use an air compressor,make sure you have an inline air dryer hooked up prior to using it and have it at a low pressure if you have an adjustable air supply unit..

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So after using compressed air . Ive tried again and the same result. So I've switched with another PSU and it's gone. But in every pc I put that PSU the sound is present

vger said:

OK,it may be a good time not to use that old psu again. If it should happen to fail/blow! The power surge could damage your mobo...

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I'm sure I'll throw it away. Ty so much for help. Have a good day!