We help IT Professionals succeed at work.

Motherboard fails to post BIOS: CPU Fan spins but no video or system boot.

copeasetic
copeasetic asked
on
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

Summary:
I am a system integrator and I am building a client a small footprint workstation with the above hardware configuration.

Problem:
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.  

Troubleshooting efforts:
 - Removed the board from the chassis to troubleshoot the possiblity of a short.
 -No effect
 - 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.

Any thoughts?
Thanks in advance!
      
Comment
Watch Question

Check RAM is on the Mainboard Qualified Vendor List. I have had similar problems although the CPU fan not spinning up when HDD power connected is a strange one on me.

Author

Commented:
I have double checked the memory QVL and determined the memory I have installed is not on the list. I have ordered new memory and will post my results once I get it installed.
CERTIFIED EXPERT
Distinguished Expert 2019

Commented:
you connected the aux 12V power connector ?

Author

Commented:
In response to nobus -

Yes, I have connected both the main ATX 24 pin power connector as well as the 4 pin 12v CPU power adapter. I have tried this with two separate power supplies as well as on another ATX systems which did power up.
CERTIFIED EXPERT
Distinguished Expert 2019

Commented:
since you swapped everything, i suspect you either made somewhere a mistake, or have more than 1 problem. that is, if the new memory does not help you farther

Author

Commented:
Here's an update:

I swapped out the chassis, changed the mother board to: P5KPL-VM and used QVL memory. I tried the CPU, memory and power supply on an ATX system and they all checked out. The only thing I can think of is the chassis is not designed to run this combo of components. I am using the LIAN LI PC-A01. It says it is ATX 2.0 compatible. The motherboard is a MicroATX...

The system just will not boot. The CPU spins for 1 second and stops. Same issue as before.

This is maddening.

Author

Commented:
I just determined that the hard drive has been the cause of the failure. Can someone tell my why a hard drive would prevent a machine from powering up?
CERTIFIED EXPERT
Distinguished Expert 2019
Commented:
it can easily, since it is connected to the disk controller interface, in fact, all device can lock up a pc
in fact, i made a mistake : "since you swapped everything"   --> you did not apparently; sorry for that...
Sorry - been away.
That's the great thing about PCs anything can cause just about any problem!
I once had a network card that when used with a particular mainboard caused the floppy drive to fail formatting floppies at 99% and I swapped out all parts in that PC twice over before determining the problem!
Glad to hear you sorted it in the end.

Explore More ContentExplore courses, solutions, and other research materials related to this topic.