Excuse me as I am fairly new to computer building and such...
my motherboard is an Asus M4A78T-E
Graphics: Asus Radeon HD4870
CPU: AMD Phenom II x4
Ram: G.Skill Ripjaw 12GB
Power: OCZ 700w
HDD: Samsung HD103UJ
So I received this computer as a gift few months ago, it had been used for about a year. About a month ago, it just died. It would power on, but no display, no beeps (no sounds what so ever), none of the usb ports worked, fans came on, and I couldnt shut off the computer unless I shut off the PSU though the back switch. Prior to this happening I did switch ram, from 4gb Corsair DDR3 to the G.skill, but it had worked fine for 2 weeks.
I tried to do my own research, then i just gave up and took it into a shop (free diagnostic, why not, I guess) and they told me it's most likely the motherboard. Today I got a hold of another M4A78T-E (bought it cheap from a friend, worked) and I hooked it up, this one beeps and such but still no display and all the same symptoms. I tried booting it up without ram, with a stick of ram, tried the corsair and g.skill, without a gpu, and i get nothing. I put my finger near the heatsink and it was warm, so I assume that's a good indicator that it's not the CPU? I don't know what else to do, any help would be much appreciated. Thanks