I recently built a new PC (my first time) and it didn't stay on longer than about 30 seconds with the PSU I initially bought. I just put in a new one I got from a friend today and it will stay on as long as I need it to, though I seem to have to shut it down by flipping the switch on the PSU >_>

Anyway I've hooked the monitor to the right spot and turned on the machine, but the monitor doesn't do anything in response. I'm fairly sure the rest of the ports are working, since the light on the ethernet hole comes on.

Any ideas?

Hi there and welcome to PCHF.

Let's deal with your topic in 2 parts;

1) I think you may have wrongly connected the PC's main on/off switch - re-check your connector POWER SW on the motherboard and make sure that the header (connector) is around the correct way.

2) Re-seat the graphics card and check thoroughly that you have connected the VGA plug to the correct connector and that it is secure.