Sick of politics here? Fix my computers!

[Daseal]

I’m currently having problems with two computers. The first is a Dell Inspiron 9300 laptop. I thought initially that this problem started from a jolt it may have taken when I slammed on the breaks in my car and had it flop off of the seat onto the floor (figures, the one time I don’t secure it this happens!), but the computer did work fine for about a week and a half after that incident. What happens is when you move the computer, it will make a sound similar to the grating noise you hear when plugging speakers into a sound card. Then the computer locks up and the screen stays on, but the touchpad and keyboard are unresponsive. It got progressively worse as time went on, and occasionally it would give me an NMI: Parity error. I figured hard drive, but after doing some research I found that could also relate to the hard drive and CPU. More and more signs pointed to the hard drive. I replaced the hard drive, and still get the same problems. I’m now fairly certain it has something to do with the power supply. When I connect/disconnect the power cord it will make that metalish noise sound that I mentioned earlier and freeze up.

Secondly is my desktop. This computer seems to randomly completely shut off. I can power it back up immediately, but depending on how long I leave it off and unplugged the longer it will work. Sometimes it will go for days on days before doing this, then for whatever reason it will crash. I’m pretty sure this is a power supply issue. I feel like with the extras I’ve added on perhaps I’ve stressed my current PSU and it can’t handle everything. When it shuts off my CPU temp has been anywhere from 85 – 105 (all F) so I don’t think that it’s an overheating issue.

I guess my question is, do both of these issues sound like power supply issues? If so, what size PSU should I get for the desktop (I assume the laptop has limited power supply sizes.)? And what could cause both of my computers to die, but no issues to my roommates? Just coincidence? It’s possible that my roommates computer wasn’t plugged in at the time, but most of the time it is. I’d appreciate any insight you guys have. Thanks!