Strange fan

I put an amd 6000 dual core cpu into a gigabyte mb. The heatsink fan are supplied with the cpu.
I hit the start button on the case the powersupply fan goes, the case fan goes and the heatsink fan goes for a few seconds then stops.
Now i automaticlly think it is faulty so i remove it and take out the cpu so as not to cook it.
I sit the heatsink on the case and hit the power button and the heatsink fan goes perfectly.
So i put the cpu back in put the heatsink back on hit the power button and everything goes except the heatsink fan which did its 2 second rotations and stoped again.
So i take it out again and try it on the case and it goes perfectly.

Then i get a heatsink from a amd 5000 and put the cpu back in attach the fan and it goes perfectly, actually run for hours.
So i take it out and replace it with the 6000 fan and back to square 1.
Any suggestions?

Anne, a couple things to check out.
Something like fan target needs bumped up, or disabled
or it maybe the current temp cut off temp is set to low.

That doesn't explain why the fan from the 5000 cpu works and the 6000 doesn't.
But in the bios i found a few fan controls.
CPU warning temperature disabled
CPU fan fail warning disabled
System fan fail warning disabled
CPU smart fan control enabled
CPU smart fan mode auto
System smart fan centre enabled

It show the cpu temp at 39 to 40 useing the fan from the 5000 cpu
so instead of disturbing everything again i may leave that fan on the 6000 cpu.
Thoughts on that please?
Thanks

CPU warning temperature disabled


Enable that and set it for 65 C.

Also check to see what BIOS version you must have for the 6000 cpu, then compare it to the one you have installed.

Acting like either a possible heat problem or you may need a BIOS update.

Bios is ok i have used the same model mb with 6000 cpu before.
If it is a heat problam why is the fan from the 5000 cpu not shuting down?

I sure hope someone can tells us as I have no ides.

How many wires are there on the 5000 fan, and how many on the 6000?

3 on the 5000 and 4 on the 6000

That'll be the reason then, the 5000 fan lacks the sensor and so runs constantly, where the 6000 one is controlled by the mobo.

CPU Smart FAN Control
Disabled Disable this function.
Enabled Enable CPU Smart Fan control function. (Default value)
a. When the CPU temperature is higher than 60 degrees Celsius, CPU fan
will run at full speed.
b. When the CPU temperature is between 50 and 60 degrees Celsius, CPU
fan will run at high speed.
c. When the CPU temperature is between 40 and 50 degrees Celsius, CPU
fan will run at medium speed.
d. When the CPU temperature is lower than 40 degrees Celsius, CPU fan
will run at low speed.

Need to set that right also.

You are quite right Train.Thanks. Seems the smart fan control is not so smart.
I disabled it and put the 6000 fan back and away it goes no problem.
I wonder if i were to cut the forth wire would it do the same thing.
Thanks again we are alll now a little wiser.

You can replace the fan in fact.

Get one with the 4 wires needed. They are not that expensive.
Then you can re-enable the temp protedction.

Are you suggesting that it is the sensor in the fan that is at fault?

The problem is the one fan does not have all the wires it needs.

The sensor is built into the motherboard. The 4th wire is what is needed.