I am working on HP 520n comp w what I thought was a power supply prob. I replaced the p.supply with a general unit and it booted up with no problems. I turn the comp off no it would not boot actually the unit would not power up. I rechecked the pw no prob,resseated the memory , no luck. N E suggestions welcomed

Does the computer turn on at all when you press your power button?

If not, you may have installed your motherboard wrong? and have a peg where the screws go in, in a wrong place, and toasted your mobo, if you didn't just install a new mobo, then maybe try getting different RAM...

the comp worked before I turned it off,actually I left it on most of the night but it won,t turn on today. Just wonder if there are any suggestion on what I may have missed