Basic Troubleshooting Trick:
Make a little not of where everything goes...... Yank it all out so you basically end up with:
Mobo + cpu + memory + videocard connected up (and the required fans of course)

(also take the memory + videocard out and reinsert them)

Than see if that works. Still not working make sure that all the little riser bits on which your mobo rests in your case are actually lined up with a hole in your mobo.

If you do get an image now keep adding stuff 1 by 1 until you don't anymore. Don't forget to switch the pc off and stuff before you take anything out of put anything in!!!.

By elemination try to find whats causing your problem.
Also does it by any chance make any beeps? As those beeps (long and short ones) normally tell you where the mobo thinks the problem is.

I'm too scared to take stuff out. Majority suggests it's the video card which was fine before it went into the shop. Will go kick people tomorrow

(Edited by Teresa 23/07/2004 19:38)

In blonde speak = its FUBAR

Sounds to me (as long as you're not hearing a continuous beep when you switch it on) like the graphics card isn't working properly or isn't properly seated (plugged in) in the motherboard. A healthy PC will normally beep once shortly after it has been switched on. Several short beeps is normally a sign that a component (such as the graphics card) is not being recognised by the system.

When you take it back to the shop it should be fairly simple for them to check out.

The other possibility would depend on how old your monitor is. I have seen very similar symptoms on new (or recently upgraded) machines where the graphics card is sending the signal to the monitor at a refresh rate the monitor simply can't handle. To avoid overloading and going "phut" (technical term ) the monitor quickly switches itself off (as described). I have seen this at first hand and as soon as the PC is plugged into a newer monitor it's as happy as anything.

if the new motherboard has built in graphics then it will use that by default until if turned off in the BIOS. plug the monitor into the onboard video output and then restart. if you get a picture then you can go into the bios and turn off the onboard video, then plug the monitor into the other video card and it should work.