So my PC was left turn off for 2 months while I was away. When I turned it on again for the first time it loaded up and I got to desktop, no problem.But there was a loud rattling coming from inside it. I would guess it was coming from the powersupply but i'm not 100%. I turned it off, later that day I turned it back on and it did not work. The power supply comes on, all the fans are spinning but there is no signal to the monitor. Plugging in a key board and pressing the caps lock key, it does not light up telling me that its not getting as far as the login screen. The only friend I have who knows about computers is long distance, I described the problem to him, he thinks the power supply is not producing enough power and needs replacing. I have checked everything inside to make sure nothing has come lose from it being moved around and it all looks good. I'm a student and do not have a lot of money to buy parts or pay for a shop to fix. I'm pretty sure its the power supply but just wanted some opinions on what it could be or how I can test to find out whats wrong exactly. I don't have another desktop or any spare parts, just a laptop. Thanks.