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December 13, 2009

Is my mobo defective or am I missing something?

This is a new pc, just built. Here are the PC specs:

Crucial Ballistix Tracer 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory

AMD Athlon II X4 630 Propus 2.8GHz Socket AM3 95W Quad-Core Processor

SAPPHIRE VAPOR-X 100269VXL Radeon HD 4890 1GB 256-bit GDDR5 PCI Express 2.0 x16


I assembled everything yesterday; and on the first boot up, 1) BIOS did not show up 2) the mobo did not beep 3) the mobo LED did not light up. It could not have been a power problem because the LEDs and fans of my chassis worked, and the power button on the front header turned on my pc. Also, it should not be a problem with my mobo receiving power since the heatsink was working. So, I disassembled everything but the cpu, mobo, and RAM and tried it: same problem. The cpu was properly placed in the board as well. Also, it should be noted that the front header power button turned the machine on, yet when held down for several seconds/minutes, the system did not shut off.

Has anyone had this problem. Is the mobo defective or is something missing?

Did you remember to plug in the extra 12V 4 pin onto the mobo in addition to the normal 20 pin power plug?

I just built a very similar PC with the same motherboard and the OP's described issue occurred to me because of this.

Do you have onboard VGA? If so I'd try it with the minimum ram it would run with, with everything possible disconnected, e.g. all.any PCI cards.

Try setting the clear CMOS jumper also then booting. It seems like a PCI host/Southbridge issue.

It's probably one of those. I have before booted up and thought a computer was broken before realizing it had an onboard video card. And have had a computer not boot, but boot up fine after clearing the CMOS.

Plus if you remove the add-on video and clear the CMOS it should boot up with the onboard card for sure. If so, go into the bios and change it to first boot from PCI-E instead of onboard. Shutdown, put PCI-E card back in and it should boot fine.

Hmm, I'd check to see if that card takes a six pin PCI-E power plug as well. That'll take down the PCI host if it's missing. I did that to a 9800GTX not long ago. Forgot to plug it's power conn in and the box wouldn't boot.

ake a stick of ram out, try with a single stick at a time.

do you have a CPU or Mobo you could borrow to test?

Another quick suggestion: Make sure your RAM is in the appropriate slot, some motherboards are really difficult about where the RAM goes.

I would reseat the processor. But definitely pull out the ram, run it one stick at a time.

Some mobos use 2 power wires (a larger 24 or so pins... and smaller 4-6 pins)

Did you plug in the CPU power?

Unplug both sticks of RAM, and turn it on. The MB should beep at you if power, CPU, and MB are all working fine.

This sounds pretty familiar--I recently built a new PC, and one of the two RAM sticks were defective. It still worked fine with the other one by itself though...

Unplug all you can, drives, chassis stuff, vgacard.

Check if your psu is powerful enough, also check if all the powercables are connected.

Check if the cables in the chassis panel are correctly plugged in, especially the speaker.


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