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My case fans plugged into motherboard don't turn on and no video

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June 20, 2012 3:41:32 AM

I just put my new build together and I have ran into a problem. I plugged all my case fans into the motherboard fan headers. I plugged my power supply into the "pwr fan" header, it is a 4 pin going into a 3 pin header. When I press the power button the computer turns on but I get no video signal. I have the vga converter from dvi that came with my radeon 6950, not sure if that is an issue. Still besides video, I noticed that not one the 3 case fans are on/spinning. 2 are brand new with the case and one I just took out of my previous computer, it was working prior. The other thing I noticed that is wrong is I cannot hold the power button and turn it off. I have to turn it off via the power supply button. When I was hooking up the front panel buttons/lights the case connectors and the motherboard diagram were not exactly identical. The video card, cpu heatsink fan and psu fans all work.

I find it odd that I don't get a video signal and also do not get power to case fans, makes me think that the motherboard is faulty. I am hoping I have something plugged in wrong could cause all 3 fans to not work plugged into 3 separate headers. I don't have an internal speaker to listen for post, or error beeps. Anyone that has had a similar experience with case fans not working and video simultaneously? That is the only thing that makes me think it could be me, because its not just one thing. Should I reseat the cpu/heatsink? Could that even cause things like this?
June 20, 2012 5:41:03 AM

wadezulauf said:
I just put my new build together and I have ran into a problem. I plugged all my case fans into the motherboard fan headers. I plugged my power supply into the "pwr fan" header, it is a 4 pin going into a 3 pin header. When I press the power button the computer turns on but I get no video signal. I have the vga converter from dvi that came with my radeon 6950, not sure if that is an issue. Still besides video, I noticed that not one the 3 case fans are on/spinning. 2 are brand new with the case and one I just took out of my previous computer, it was working prior. The other thing I noticed that is wrong is I cannot hold the power button and turn it off. I have to turn it off via the power supply button. When I was hooking up the front panel buttons/lights the case connectors and the motherboard diagram were not exactly identical. The video card, cpu heatsink fan and psu fans all work.

I find it odd that I don't get a video signal and also do not get power to case fans, makes me think that the motherboard is faulty. I am hoping I have something plugged in wrong could cause all 3 fans to not work plugged into 3 separate headers. I don't have an internal speaker to listen for post, or error beeps. Anyone that has had a similar experience with case fans not working and video simultaneously? That is the only thing that makes me think it could be me, because its not just one thing. Should I reseat the cpu/heatsink? Could that even cause things like this?


Did you make sure that you have connected everything on the motherboard?
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June 20, 2012 1:53:57 PM

Yea I checked and double checked. I reseated the cpu, reapplied the heatsink with new thermal paste. I put an older pci-e video card in to make sure it wasn't my new card, to no avail. The heatsink fan comes on, the psu fan comes on and the video cards fans come on. All 3 case fans still do not come on at all and the I have no video signal from two different video cards. I reset the cmos according to the motherboard manual, still nothing. It's really looking like I have a bad motherboard. But the fact that the heatsink and video card fans are spinning makes me think there could be a chance of improper connection. Besides the the front panel connections everything is pretty straight forward. I dont have any cables that aren't plugged besides extra leads from the power supply.

If the case or something was causing an electrical issue I would think that nothing would turn on if the motherboard was shorting out. I thought about getting adapters for the case fans to plug into the psu but that wouldn't help the no video signal issue. So it seems my power supply is fine, everything else I have no idea because I don't have video or a speaker to see if its passing post.
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March 22, 2013 4:04:54 AM

wadezulauf said:
Yea I checked and double checked. I reseated the cpu, reapplied the heatsink with new thermal paste. I put an older pci-e video card in to make sure it wasn't my new card, to no avail. The heatsink fan comes on, the psu fan comes on and the video cards fans come on. All 3 case fans still do not come on at all and the I have no video signal from two different video cards. I reset the cmos according to the motherboard manual, still nothing. It's really looking like I have a bad motherboard. But the fact that the heatsink and video card fans are spinning makes me think there could be a chance of improper connection. Besides the the front panel connections everything is pretty straight forward. I dont have any cables that aren't plugged besides extra leads from the power supply.

If the case or something was causing an electrical issue I would think that nothing would turn on if the motherboard was shorting out. I thought about getting adapters for the case fans to plug into the psu but that wouldn't help the no video signal issue. So it seems my power supply is fine, everything else I have no idea because I don't have video or a speaker to see if its passing post.


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March 22, 2013 4:10:16 AM

Hi Wade,
Not much of a solution here, just an almost identical problem.
I've just put my first system together from components and have very similar issues. 2 of 3 chassis fan headers don't work, no video signal at all from any video output and shut down after 20 seconds or so. Reseated the cpu and redid thermal paste from stock, no change. I'm suspecting with the fan header failures and no video it's a motherboard issue. The psu's almost brand new and was fine last night in my old pc.
How'd you get on?
thanks
Brendan
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