4-pin CPU fan 3-pin motherboard header

[Cruendithas]

I installed a Be Quiet! Pure Rock CPU cooler, but the included 4-pin fan will not work on the 3-pin CPU header my motherboard provides, no matter how I situate the pin connection. The fan will run at startup for a few seconds then turn off. My motherboard is a crappy stock thing that came with an assembled PC (HP pavilion p6740f). The motherboard only possesses 3-pin connections. The BIOS settings does not include "CPU smart fan". Is there a workaround without replacing the motherboard (present budget restraints)?

UPDATE: I decided to just leave the fan off until I eventually get a new motherboard, seeing as how the heatsink itself keeps the CPU (3.2 GHz 4-core not overclocked) at 30-35 C idle and 40-45 C with the load I put on it. I do, however, appreciate the advice.

 

[alexoiu]

An option would be connecting the cooler to the power supply (using a 3 pin to molex adapter). In this case, the fan would run at max speed all the time. Or using a fan controller (more expensive).

 

[13thmonkey]

get a 3 pin fan? imagine it's a std 120mm fan.

 

[Michal_8]

Connect the Fan on molex cable for power(first 2 pins) and use the PWM or sense pin(3th and 4th pin) and connect it to the third pin on the mobo You need to test one of the options will work as for me I have 2 fans controlked by motherboard booth powered up from molex and to control them via mobo have to connect the sense cable from booth fans (4th pin on FAN connector) to the 3th pin on mobo instead of usual (3th pin on Fan) PWM cable.