Im building my computer as I write this. My PSU has a fan on the top of it. My case has no outlet on the top of it. can I turn the psu upside down so the fan will function or is this a bad idea?
That is a very good idea. The only problem is that the power cord will then be upside down (technically), but it's not really a problem. I suggest flipping the PSU to have the fan facing the motherboard.