I have a dimension 8400. Recently it stopped working. The motherboard light would come on but the pc would not. So I purchased a new power supply. Problem solved!! However after two months the pc will not turn on. About two days ago it restarted by itself on two separate occasions. Now it it won't turn on and the motherboard light is not on. Is it a bad power supply again or something worse?
Well there is your problem it is a junk PSU any ATX PSU will work in your system get a good brand SeaSonic, Corsair, Antec, Silversone, and some of OCZ PSU's are half decent dont look at those sites saying that its specifically for your DELL blah blah its total BS your Dell uses a universal ATX PSU so go to www.newegg.com and pick one out with in those brands that suit your needs and you should be fine.