<human>: My computer started to sound like this a while back, almost a year ago. So i simply took off all of the chords and pulled my monitor, keyboard, and mouse off my desk and filled the space with my laptop. This worked for a while but i want to be able to use my laptop in other places, as is i treat like a desktop, which it obviously is not. 

So today i decided to open up the my computer, on its side. Worked fine, left it on for an hour or two, came back, nothing. I was stoked. Then when i popped it up on it's side, it did it again. So with the side off i looked around and came to the conclusion that it is the fan on the power supply that is making the noise. For a while it would speed up then hit something or something and stop, then repeat. But now it's constant. When i layed it down on its side it stopped, but not anymore. 

Right now i'm running the computer with it's side off facing away from my desk so it won't heat up. Which, is working nicely, except for the noise.

Reddit what should i do? Replace the power supply or fix the fan? I tried to pull the power supply out. I unscrewed it, but it wouldn't come out, who knew there could be so many damn chords coming from this box >.<. Is it possible to replace just the fan? that could be cheaper, right?

Summarize the given text in a few sentences.
<bot>: the fan in my computer's power supply is off balance or something and sounds like a lawnmower, please help.