Hp pro 3500 mt series desktop/ 511-cpu fan not detected

[LerayMe1111111]

• Hello, I have a problem, which is that when I turn on the HP Pro 3500 MT Series desktop computer, the processor fan does not complete three cycles and remains stopped and appears on the computer screen as 511 - CPU fan not detected. When I press F1, the computer runs normally with the fan constantly stopping, and this happens whenever I turn on the computer again, please, what is the problem? Could it be the motherboard or the fan itself?

[BeemerBiker]

You have a 4 pin fan jack.  Make sure the cable connects to all 4 pins.  I is easy to be off by one pin

Check the cable to see of one of the wires is damaged.

[LerayMe1111111]

I have checked it, sir. It looks good and there is no problem. The problem is when I turn on the computer, the fan rotates approximately four revolutions and stops, and the computer continues to work even though the fan stops rotating completely, and this happens whenever I turn on the computer again.

[BeemerBiker]

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@LerayMe1111111 wrote:

I have checked it, sir. It looks good and there is no problem. The problem is when I turn on the computer, the fan rotates approximately four revolutions and stops, and the computer continues to work even though the fan stops rotating completely, and this happens whenever I turn on the computer again.

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I suspect the fan has a problem.  There should be a setting the the BIOS for fan speed.  Set it up high and if the fan does not respond it needs to be replaced.  You should have another fan in your system. It is only 3 pin but it also needs to spin for the F1 warning will show up.