Asus P5B mobo - new comp wont power up.

Hi there, im currently building a new computer for my parents and its turned into a little bit of a disaster. I've built a few computers before and never had a problem:

The setup im using is:

Asus P5B (standard) mobo
Intel C2D E6550
2GB (2 x 1gb dual channel) OCZ Nvidia SLI RAM PC2-6400
XFX Geforce 8800 GTS 320mb
Sata HDD
IDE DVD drive
FDD
550w PSU

now, the problem is that the computer powers on for a few seconds, turns itself off for another few seconds, and then powers itself on indefinetly. However, there is no RAM beep, only a tone as it powers off the first time, and again if i turn it off by the switch on the case. There is also no output to my monitor.

This problem is alsmost certainly the mobo as i have tested everything else:

- the processor works fine in my other computer
- the 8800 is my old one and works fine, neither does a 7600 GT work
- Ive tried some other OCZ ram to no avail (i cannot check the new ram as my old mobo is not compatible)
- Ive tried a brand new sata hard drive, as well as both of mine
- ive tried a spare PSU (also 550w)

This power problem seems to have happened before, however others have had output from their graphics card.

Any help would be greatly appreciated. Thanks

yay... never mind, this is the most stupid of problems... anyone else having this sort of issue, go here:

http://vip.asus.com/forum/view.asp [...] uage=en-us