About two weeks ago my computer suddenly just went dead and wouldn't power back on. It's older, so I figured it was either the power supply or the motherboard had died.
I replaced the power supply and it still wouldn't power back up. So I got a used (known working) motherboard and put it in. It still won't power on.
Anyone have any suggestions what to look at next as a possible cause?
Boris 24
Make sure outlet is alive,cord is good.
tumbleweed_biff
If you don't get a beep code, then it probably isn't RAM. I would expect CPU given what you have described and already done.
Strip down to the most basic elements: motherboard, power supply, one stick of known working RAM, minimal graphics adapter. See if it will boot at that point and then see if it will boot from a USB drive. Once you have a working bare bones configuration, move on from there, adding things in one at a time.
Anonymous
It's look like a motherboard problem. You may learn about motherboard from here:
http://ctoptips.blogspot.com/2014/01/how-to-setup-motherboard-in-computer.html
two_swords_as_one
on/off switch/button and some computers will not turn on if one of the cooling fans is bad.