Have I got 2 broken PCs?

Hi, shorttime lurker with finally something to post! I've just built myself a new computer, Sempron 2800, 512mb on a PcChips M848ALU but when I went to turn it on, I get nothing. No boot, no beeps. I tried the Sempron and the ram in my old PC and both work fine so I assume it's a dodgy motherboard? BUT now I've put the old PC back together with it's own parts, I'm getting the same problem. There's no way that the parts coming from the dodgy motherboard could have killed a healthy one is there? And is there a way I can check that the motherboards?
Cheers!

 

welcome to the forums!

the only way to check motherboards is to plug in components to make sure they work. so unless you have another processor, ram, etc around, then yeah.

but here are a couple things that you should check: is the heatsink mounted on right? is the ram pushed all the way in? don't be afraid to use force. are the pci/agp cards in all the way?

 

also look to see if you have the PSU pluged in to the wall or the mobo lol