Intel® Desktop Boards
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why DQ45CB flashing power LED


I got a PC with DQ45CB mainboard.

When plugged into mains power, the front panel power LED flashes approximately once per second.

It will not boot when the power button is pressed: no beeps, no fans, no drive lights.

I have looked into the documentation for this mainboard, and see nothing about flashing LED.

The green standby LED on the board is lit up. I have plugged the power supply into an ATX tester, and it has all the voltages except legacy -5 V.

I checked all the connections on the board, nothing is loose, and front panel wiring is on correct pins.

I removed the RTC backup battery overnight to clear BIOS. Tried again next day - still the same.

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2 Replies

Hi Michael Seman,

I recommend you clearing the CMOS on your board by disconnecting all components and taking the battery out for about 20-30 minutes. If possible, do this process having the motherboard outside of the chassis.

Another good step I can recommend you is to test another monitor, power supply and cables in this way we can discard possible problems with other components.


I have disconnected everything except the power LED (even CPU fan). It still blinked.

The monitor is irrelevant, as it was not powering up, just stuck in standby state.

I also tried another power supply. I read somewhere else that this board should have an ATX 2.2 power supply, so I used a new power supply that complied. Finally put the board in another case, but no help.

When I removed it, I also checked to see if there might be any loose screws or such that might short out PCB tracks, but only a lot of dust.

So I concluded that the mainboard was defective. I removed the CPU and put it in another board, and the CPU is working.