Computer will not boot. Help!

[douglasparler]

First try I got to install and many programs then plugged in a usb and died would not reboot.

So I am on my second Motherboard (gigabyte h87). Put the board in, worked for a bit then restarted which it wouldn't boot after shutting off. I have a i5 4570. Antec gx500 is the case.

When I hit power switch fan in psu makes a quarter spin then stops. Also Ethernet port is lit up. Any suggestions would be much appreciated as I have to RMA by tomorrow.

Thanks!

 

[rhapdog]

A power supply on the verge of fail may not be able to supply enough power to boot up the system, and would give the symptoms you describe. A defective motherboard could also give those symptoms, but with a second motherboard already being tried, I would suspect the power supply. Only thing is, if the power supply is bad, it could have possibly damaged the motherboards as well. I'd probably RMA the whole thing if it were me.