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On Boot CPU fan Spins then Stops, Computer starts as normal

by AwesomeAndy / March 16, 2005 4:15 AM PST

I am running an AMD Athlon at 1 gig on an Asus A7V Mobo. Everything was working fine until I switched cases. Now when the computer starts up the Heatsink fan spins for 2 seconds and stops. All the case fans still spin and the computer continues to run for a few min then over heats and quits. Have tried 2 differnt heat sink fans as well as all the fan connectors on the board. Not post problems. No Bios Settings. HELPPPPPPPPPPPPPP?!?!?!?

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Possibly the controller chip is bad.
by Ray Harinec / March 16, 2005 4:59 AM PST

Just get a 3 wire to 4 pin molex and try running the CPU fan from 12 volts constantly [or use a fan with the molex connector].

The fact that you switched cases makes me think that you have managed to short something out from the mobo to the mounting plate. Try running with the mobo laying on a sheet of cardboard, completely insulated from the case.

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Recheck your work
by Willy / March 16, 2005 5:19 AM PST

You may need to breakdown the system again, in order to closely inspect for any shorts and/or unintended contacts. Verify under bios setting if your able to see long enough any cpu temp reading. Are they normal or within desired levels? Don't take anything for granted, check it. Also, verify proper harness hook-ups, etc. cpu fan vs chassis fan connector!

enjoy -----Willy Happy

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I have a board like that....
by R. Proffitt Forum moderator / March 16, 2005 5:24 AM PST

The CPU fan seem to overtax the motherboard CPU FAN connector's power. I found another connection called CASE FAN1 and used that.


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Tried a Few things last night.
by AwesomeAndy / March 16, 2005 9:19 PM PST

I have tried all the Case Fan/CPU Heatsink fan connectors and get the same thing. (POS!!!!) I dissconnected and took everthing out of the case last night so it was just the PS, Mobo and chip.... Got the same thing... The only thing left to try is taking the mobo out and setting it on some carboard and givin that a shot... Other than that I think its gonna be the 12v connector Idea.... Thanks for the posts.

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by Willy / March 16, 2005 11:36 PM PST

Some fan connection points can overtax the "solder lands" if too much is on demand. Older mtrbds. tend to do that due to poor quality and/or power supplies not deleivering stable juice. A direct connection resolves this as you may find. However, if all else fails, some mtrbd. makers(Abit, come to mind) had a bios update that addressed fan RPM monitoring glitch, do a bios update. As for bios updates, the support website may have a bios history on just what each bios updates does, check it. However, I do think you have a reliable power problem, either connection or p/s.

good luck -----Willy Happy

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Wierd Thing Is
by AwesomeAndy / March 17, 2005 2:02 AM PST
In reply to: Power

Everything has been running with this exact hardware config for probably 2+ years without issue... Just Started when I changed the case. So I dont think its the fan overtaxing. Who Knows though... I have a new PC on order anyways so if this doesnt work.... Well **** happens.

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