Help!, New PC dosen't work!

[bags]

I recently built a computer consisting of an ASROCK (Socket A) motherboard and corresponding AMD Athlon 2600+ processor. The computer also has 512Mb DDR memory, 350W PSU, 128Mb Nvidia Graphics card, DVD-ROM drive, 40GB 7200rpm harddrive and standard floppy. When I powered up the computer, all the fans (case fan, cpu cooler and graphics card fan) ran, the connected monitor clicked on. After about five seconds with no display on the monitor the PC switched off. It has done this every time I have tried it. I have tried with different Ram and also with the unessential devices disconnected. I have also tried it with a different graphics card. However still no luck! I have spoken to some other people about this, but they cannot offer any more advice. Can anybody help me? Please!!!!!

 

[devlish96]

proceed as "micro" suggested,.when these mobo mounting screws get grounded you wont be able to boot your pc. i use 2 layers of scotch tape.