So here's my problem:
I have an MSI 865PE Neo2-P Platinum motherboard and it's not booting up. There are no diagnostic beeps or anything. The hardware simply powers on and that's it. The lights flash on my DVD drives and the fans run etc.

Here's how it happened:
I had my computer powered down and I unseated one of my 256mb DDR RAM sticks and reseated it. After that I had the problem I described. Also I recently installed a new graphics card though I doubt that has anything to do with this because the PC was working fine for a week with the card in.

this sounds like it could be your CPU or motherboard...

if the ram was faulty/damaged then you should get bios beeps...

what comes on on the screen?

have you tried un-plugging your graphics card and trying your old one?

Yeah, I tried replacing my graphics card with the old one. That didn't help at all. I also tried completely removing the stick of RAM that I had reseated and that didn't help, nor did removing all of the RAM.

Nothing comes on the screen.

My initial thought was that it was the motherboard also.

i dont really want to say "you need a new CPU" incase it is the motherboard that needs replacing...

i do not think this problem is caused by the hard drive, RAM, graphics or sound

the problem is most probably the motherboard or CPU

when my motherboard broke, it broke completely.... i didnt get any lights or fans or anything!!

i did have a similar problem to yours, the CPU needed replacing.

i would sugest that you remove your CPU and re-fit it as it may have come un-seated when you were installing your graphics card.... if that doesnt help, you will need to replace the cpu/mobo

sorry i cannot give you a definate answer
Mike

EDIT: i would go to your local computer shop to buy a CPU and ask them if you can take it back if the CPU is not the problem that way, if it doesnt work.... take it back and get a MOBO (make sure you get the correct socket for either the CPU or mobo and correct memory type e.g. DDR SDRAM for the mobo so you dont need to buy more RAM)