PC not rebooting

[fangio99]

Current Spec

Antec Sonata Elite Case
Antec Truepower 750W PSU
Asus P5Q Pro motherboard
Intel Q8200 Processor
Kingston HyperX KHX8500D2K2/4G 2x2GB Ram
2x WDC Caviar RE2 GP 1TB hard disks in RAID1 Mirror using Intel Matrix Storage Manager
LiteOn iHAS322 DVD/RW SATA drive
Sapphire Radeon HD 4850 1024MB PCI-E
APC Back Ups ES 700VA
5.25" Front panel Card reader with Esata and USB ports
Samsung 23" Screen

So far the hard disks, the PSU and the UPS have been replaced. The CMOS has been cleared countless times.

The PC works fine except for not rebooting. It reboots from the OS with no problems but if I enter the BIOS even to check the settings or boot from a CD, it wll not reboot at all. No lights, no activity, no display but the PC is on. It doesn't even do the POST. The only way to clear it is to remove the power connection completely for around 30 seconds.

Please anybody got any ideas before it goes out the window. This is a brand new system that has never worked properly.

Fangio.

 

[nickbits]

FYI reboot != boot

 

[fangio99]

What I mean is if you remove the power for 30 seconds you can do a cold boot with no problems. Also you can shut down and restart from within the installed OS. It is only when it tries to restart from a Boot CD or from the BIOS that the problem occurs. Hence my usage of the word "Reboot" rather than just Boot.

Fangio.

 

[o1die]

I would flash the motherboard bios using the crashfree bios program on your motherboard cd. Read instructions carefully, or you could end up with a dead motherboard. It will tell you when the flash is done and when to reboot your system. It can take several seconds, so don't do anything until it tells you it's done.