# Motherboard power and reset light flashing



## twbaker (Sep 20, 2009)

Hi everyone,

I'm currently putting a new build together with the following spec:

Intel i7 920
Asus p6t deluxe v2
6gb (3 x 2gb) ocz gold RAM
ATI Radeon HD 4870 1gb gpu
Zalman CNPS10X Exctreme cooler
WD Caviar Black 1tb HDD
OCZ ModXStreme 600w PSU


I'm not sure whether the problem is with the power supply unit or with the motherboard, but the symptoms are visible on the motherboard...

I had some problems getting the system running, so I removed the motherboard from the case, and removed all the components from it, except for the CPU and the heatsink/fan.

With this setup I was able to power on, and the POST beeps indicated the lack of RAM, so I added RAM. Again, successful power on, and beeps indicating lack of GPU, so I added the graphics card. The next POST gave beeps indicating the lack of connected monitor, but before testing a monitor with the setup, I wanted to re-mount it in the case. So, first I connected the case fans, but didn't put the motherboard back in the case.

When I tried to power on, the fans only span for a second before cutting out. There may have been a spark from somewhere in the vicinity of the case fans, but it may have just been the LED in the fan flashing on then off again.

Since then, I have been unable to turn the system on at all. I have now removed all the components again except for the CPU and Heatsink, but still I can't turn the computer on.

The only visible symptom I can see is that when the PSU is connected to the motherboard and is switched on, the lights in the power and reset buttons on the motherboard flash, whereas before they were solidly on. The flashing continues for about 10-20 seconds even after the power supply is switched off/disconnected.

My initial thoughts are that when the case fans shorted out (if that's what happened), it may have somehow fried something on the motherboard (unlikely because the case fans were only connected to the PSU, not the mobo). Either that, or the case fans somehow damaged something in the PSU.

I have tried testing the PSU by using a paperclip to connect the right wires, and the fan inside the PSU does spin, indicating that the PSU is at least partially working.

Has anyone encountered a similar problem or have any suggestions?

Any help would be greatly appreciated, this problem is really frustrating me!

Thanks,

Tom B.


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## Tyree (May 10, 2009)

Did you have ALL of the standoffs in the case before installing the Mobo? 
You are cutting the power pretty close with a 600W PSU. The 4870 requires a minimum 500W PSU.


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## twbaker (Sep 20, 2009)

I was testing this outside of the case on a non-conductive surface when it all happened, so I know its not shorting out on the case.

It seemed to be working at one point... would overloading the PSU cause damage to it?


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## vladimirb (Mar 31, 2008)

Maybe... Are you able to borrow more powerful PSU from a friend to test your machine???


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## twbaker (Sep 20, 2009)

Not readily available... how likely is it to be the power supply rather than the motherboard that is the problem?


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## vladimirb (Mar 31, 2008)

I am just assuming... Could be fake Motherboard...
Just want to make sure PSU is OK. If you start PC with some other PSU than most likely it is PSU problem.
Otherwise, if with new PSU you still can't get power, its leads us to Motherboard problem...


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