Computer freezing up

I already posted a similar thread in the hardware forum but no one is replying. Forgive me for starting another thread with the same problem, but I need answers on how to resolve this issue.

A friend of mine was experiencing computer freeze ups. He took his computer to a repair shop and they told him he needed another MOBO. They installed it, he took it home and it still freezes up. So, he passed it on to me.
I checked it out, the video card chipset was getting very hot even with the case off and a fan blowing on it. I swapped the vid card with another and the same thing happens. It gets very hot, freezes up and then the monitor will not display anything. I shut the computer down to let it cool off start it back up and no display on the monitor. I take out the vid card and the system will not POST, or even give a post error

Whats causing the overheating issue? Is the mobo bad?

Again, sorry for reposting this. I just need to get this resolved as quickly as possible. Thanks.

 

stick to one thread,when someone comes online they will answer
check the temps in the bios
do you get any beeps
check all the fans are operating
reseat the cpu
reseat the ram
what size p/supply
and list system specs