What should I do

[tom ogg]

Hello,Ihave lost power to my moniter and my pu emits a high pitced sund for abour 10 seconds, then stops and then it does it for 10 seconds , stope and so on and so on.

 

[o1die]

Could be a fan bearing failing, or something in the power supply. I would remove the case cover and listen to try and isolate the source of the noise.