|Your explanation is confusing with various mixed up symptoms and comments These bits make no sense:|
"The PSU is under too much voltage input, so it cannot output enough to power the PC". What do you mean?
" I don't believe the second one". The second what?
Best set out your issues in a clearer way, one by one.
If there is a whining noise from the PSU it needs replacing. It is probably the fan bearings and although it might be possible to look inside and lubricate the bearing (usually under a sticker) you have to be careful. Components within the PSU can remain charged, also it is very easy to break leads off when dismantling.
Always pop back and let us know the outcome - thanks
message edited by Derek