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Fans spin on and off before power on

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November 3, 2011 9:11:08 PM

I have just built a new system and when I turn the power on at the wall the fans turn on and off repeatedly. This is before I press the power button to boot the OS. The fans are powered through 4 pin molex's because there wasn't enough fan headers on the mobo.

I thought I may have got the front panel power switch connector in the wrong way or on the wrong header on the motherboard and after consullting the motherboard manual and checking and then double checking the problem still persists.

The PC actually boots fine and operates as normal but im concerned that this power fluctuation might damage some of the components.

Ive had a good old googling session trying to find an answer but have been unsucessfull :(  so any help wold be great

PC Specs

Core i3 540 3.10GHz @ 4.20GHz Overclocked (This came pre-overclocked in a PC bundle)
Gigabyte GA-H55M-UD2H
4GB DDR3 Dual Channel Muskin Silverline
Nvidia GTX 560
WD 1TB SATA
700W OCZ ModXStream PSU
Antec 100 Case

Thanks in advance
Phil

More about : fans spin power

a b V Motherboard
November 3, 2011 11:12:41 PM

How do you turn the power on at the wall? Does that mean plug it in? Is the power supply on/off switch on the back by the plug in the off position when you turn the power on at the wall? It should be. If it's on it's normal for some power to go to the motherboard and since you're using the molex's it might be just that initial surge. If the power switch on the psu is off does it do the same thing? And if not, like it shouldn't, do they briefly turn on when you turn the psu on/off button on the back to on?
a c 155 V Motherboard
November 4, 2011 12:23:06 AM

do yourself a favor buy a power bar to protect the mobo from power surge that could happen when you use it plug directly in wall and turn the power on
Related resources
November 4, 2011 6:10:50 PM

Thanks for the replies
When I start the PSU switch is in the OFF position and the power lead is connected to a surge protector then to the plug socket. I make sure the socket is switched off and then insert the plug and then turn it on after that then I turn the switch on at the PSU.

The fans only spin when the PSU switch is in the on position.
I also thought about the intial surge you mentioned but the fans start and stop repeatedly for as long as the PSU switch is in the on position so I don't know if that can be the case

and once again thanks in advance :) 
a c 155 V Motherboard
November 4, 2011 7:11:31 PM

check if you dont have anything that make contact to the metal of case or something else
a b V Motherboard
November 5, 2011 1:09:12 AM

I would unplug everything inside the case and start with the 24 pin connector. Plug in just that one plug and turn on the psu and see if it happens then. If not try the 4 pin power connector next. I would do that with each piece of equipment you have plugged in until you see it happen. If it happens on the first one I would try a different psu first. If a different psu gives you the same results you need to rma the board.
a b V Motherboard
November 7, 2011 11:06:59 PM

Any luck?
November 10, 2011 10:30:29 PM

Sorry for the slow reply....

After checking is any metal was touching the motherboard and then some trial and error with the PSU and tried another PSU I found that the old PSU was faulty

Thanks for all your speedy words of wisdom
suteck and scout_03 your are some AWESOME guys :D 

Thanks again
Phil
!