Same problems
Purchase HP Pavillion CMPT (P4 1.6GHz) off Eaby...when it arrived it would power on and not POST - monitor stayed in suspend mode. I tried what was sent ealier in this post except the CMOS reset (the ASUS board is custom made for HP so there are no jumpers). I figure my problem and possibly yours is that the MB is gone. If a manual reset doen't do then try a different board....
In my case it could also be someone trying to overclock the CPU and cooked it.
Another possiblility is that if you interupted a BIOS update then you've cooked your CMOS EEPROM and will need to pull it and have a shop re-flash it....
Good luck - I am buying another MB off of EBAY....