Asus M2V-MX won't boot to bios

[lowman905]

I have a friends pc that wouldn't boot to vista. I pulled the hd, backed it up then formatted it. Put it back i n the case to install windows 7 and it was hangng on the asus screen when you first turn on the pc. i managed to get into the bios but it was very slow, i reset everything to factory and win 7 hung up. I tried booted a copy of xp and it hung up. All i get is a black screen when i turn on the pc, not even a beep. I have unhook all of the drives, used a new power supply, changed back and forth between sticks of ram and evn tried unplugging the cpu fan. I removed the video card as well but all i get is a black screen and no pc beep......any ideas?

 

[lowman905]

I have also removed the mb battery and reset the cmos pins, i am begining to think the mobo needs replacing