Comp won't boot - Monitor no signal

Drakey_86

Honorable
Mar 9, 2013
1
0
10,510
Hey Tom's Hardware,

Just under a year ago, I bought a custom-built PC from a reputable UK-based company. Everything was going fine and dandy until last month. I had gone out briefly and left the comp on when I received a call from my housemate saying that the comp was making a really loud whirring noise. When I got home, the noise had quietened but the screen had crashed. So I restarted it and the problem had gone.

That was until yesterday.

I switched it on that morning and suddenly the whirring noise returned and the monitor signal wouldn't connect. After a little bit of poking about, cleaning the fans (which weren't especially dusty, I should note), the noise *eventually* calmed down. However, while it *sounds* like it's booting up and the keyboard & mouse lights come on, there's nobody home! From what I've gathered from reading related posts, this could be a PSU issue, yes? That did appear to be where the noise was coming from when I put my ear to it.

Here's my specs:
AMD Athlon II X2 250
6GB DDR3 Kingston 1333 RAM
500GB SATA Hard Drive SATA 3 HD
CiT 500W Black Edition PSU
ATI HD 6450 1024MB
CiT Vantage Black Case HD Audio Black Interior 4 Fans Card Reader
Windows 7 Home premium 64 bit


Thanks in advance.