Motherboard fails to post BIOS: CPU Fan spins but no video or system boot.
Posted on 2008-01-24
System Integration Problem
Mainboard: Asus P5B-MX
Memory: 2x 1GB Kingston KVR800D2N5K2/2G
CPU: Intel Core2 Duo E6550, JGA775 2.33 Ghz, 4MB L2 Cache, 1333 Mhz FSB
Power Supply: Thermaltake TR2 RX-450 ATX 12V 2.2 (TR2 RX-450PP)
Modular cabling power supply
Hard Drive: Seagate Baracuda 7200.10 320GB
Chassis: LianLi PC-A01
I am a system integrator and I am building a client a small footprint workstation with the above hardware configuration.
I have been unable to get the mainboard to post.
- The board's power indicatior lights up when the P/S is plugged in, but not initiated (the power swith on the p/s is switched on, but the mainboard power not initiated).
- When engaging the chasis's power switch the CPU fan starts spining, but no video or system response.
- I have tried this with the 12v power cable unplugged as well and the fan still spins, still no post.
- Same condition occurs when I jumper the pwrsw with a screw driver without chassis power switches plugged into the mainboard.
- The board does not report any error codes (no beeps from system speaker)
- Same condition occurs when CPU, Memory are the only components installed.
- When I plug-in one of the modular power cables into the power supply and connect the hard drive power the CPU fan will not spin up when the power is engaged.
- Monitor is functional.
- Removed the board from the chassis to troubleshoot the possiblity of a short.
- Swapped Power Supply (Antect 450W Smart Power ATX v2.0)
- No effect
- Tested the old Powersupply on another system and it powered up just fine.
- Swapped out the motherboard
- Swapped out the CPU
- Pulled the memory
- Tried 1 stick of memory at a time (no error reports at all)
- Installed video card in PCI-E slot (no change)
I am at a loss here. I am going to test the CPU in another machine today, but I find it unlikely two CPUs would be bad.
Thanks in advance!