This one is kinda awkward, since I'm half a country away from the machine in question, but my good friend in California finally built his own PC today... Trouble is, he can't get the damn thing to give him display output to make sure everything posts and start installing an OS.
I know he's using an Intel i7 920 and a Radeon 5870 1GB - I can get exact details on other components as needed. He's triple-checked that all the components are properly seated, plugged into the PSU, etc. He's also tried swapping the GPU out for an older GeForce (9000 series IIRC) that he knows works because it's been in use in another machine and which draws its power entirely from the motherboard in case it was a power supply issue. That didn't help. He's been testing on a VGA monitor with a VGA-to-DVI adapter. The monitor doesn't even show a black screen, just its normal 'no signal detected' type message as if nothing were plugged in. He's going to try his TV via HDMI now to see if that changes anything.
He lives nearby to the store where he bought everything, so he can take things in if needed for replacements, but it's hard to diagnose the problem in the first place without ouput. The hardware *appears* to be working fine - all the internal fans, including the one on the GPU itself, spin up, the hard drive spins up, lights come on on the mobo, and the powered DVD tray opens and closes just fine. The only indication that he has found that anything is wrong is the problem itself - no display output.
So... Any suggestions? He wants to avoid taking it in and paying them their build fee to fix it - after all, he spent a couple hours doing most of the grunt work himself already. Right now he's annoyed and confused and I don't know what to tell him. ANYTHING, from "here is your exact problem and how to fix it" to "maybe try this test" or "maybe it could be X component that's bad" would be oh so very helpful.
Thanks for the quick reply. Turns out, my buddy was using a VGA-to-DVI adapter he had lying around. On a whim, he inspected the one that came with the 5870 and noticed it had a different number of pins! After swapping adapters, everything is working smoothly and he's installing Windows on his properly POSTing new toy now.