I noticed that lately my Dimension 2350 has been acting sort of weird. I turned it on and logged into my Windows account and while it was logging in the PC just shut down. I turned it on and at the same place it would shut down. I can't figure why it's happening, my power cord is plugged in snugly on either ends. The only thing I can think of that could possibly be causing this problem is a bad power supply. But I can make certain of that, I need your help!