[SOLVED] Non-stock CPU FAN with only 3-pin and 4-pin Molex connectors ?

[rage690]

i just bought a cheap CPU fan for my old intel i5 3470 processor and ASUS P8B75-M LE motherboard
its just a computer my son plays with.

here is the link to the CPU fan TGEARS T400-2 Twin Fan RGB

now this CPU cooler is basically just a heatsink with 2x 120mm FANS attached to it
these two fans has 3-pin and 4-pin Molex connectors each, but the problem is that my motherboard CPU_FAN has a 4-pin.

NOW my motherboard is crying CPU FAN ERROR !! because i guess it couldn't detect a fan because nothing is connected to its 4pin connection.

now i do see a CHASIS_FAN which is a 3 pin connection should i connect 1 of the 2 fans of the CPU there ?

but even if i do that, with nothing still connected to the CPU_FAN 4pin port wouldn't it still give me the error ?

also if i do that, what about the other fan ? there are 2 fans on this new CPU cooler. i have no other CHASIS_FAN port on the motherboard just that one.

Can i just ignore the CPU FAN error considering the temp is not rising and is as 37-38 at idle anyway ?

 

[CountMike]

i just bought a cheap CPU fan for my old intel i5 3470 processor and ASUS P8B75-M LE motherboard
its just a computer my son plays with.

here is the link to the CPU fan TGEARS T400-2 Twin Fan RGB

now this CPU cooler is basically just a heatsink with 2x 120mm FANS attached to it
these two fans has 3pin and 4pin Molex Connectors each.

problem is that my motherboard CPU_FAN has a 4PIN

NOW my motherboard is crying CPU FAN ERROR !! because i guess it couldn't detect a fan because nothing is connected to its 4pin connection.

now i do see a CHASIS_FAN which is a 3 pin connection should i connect 1 of the 2 fans of the CPU there ?

but even if i do that, with nothing still connected to the CPU_FAN 4pin port wouldn't it still give me the error ?

also if i do that, what about the other fan ? there are 2 fans on this new CPU cooler. i have no other CHASIS_FAN port on the motherboard just that one.

can i just ignore the CPU FAN error considering the temp is not rising and is as 37-38 at idle anyway.

Check BIOS for PWM/DC(voltage) control of CPU_Fan. 3pin fans should be in DC control mode.

 

[Paperdoc]

From your mobo's manual it appears the 4-pin CPU_FAN header can ONLY do the new 4-pin PWM Mode of control. When you connect your 3-pin fan to that the fan will always run full speed, which is the SAME result as if you connect that fan directly to a Molex output from the CPU.

NOTE that you must connect for each of these fans only ONE of its power connectors. So I suggest this plan. Connect the smaller 3-pin standard fan connector of ONE fan to the CPU_FAN header. It will get power from that header and run full speed all the time. Its speed signal will be sent to the header so it is happy. From the OTHER fan use its larger Molex connector to a female Molex output from the PSU. This fan also will always run full speed, but its speed signal will never be seen anywhere.

Use the mobo's only CHA_FAN header to connect any case ventilation fans. It is 3-pin but you can use either 3- or 4-0pin fans on that, although 3-pin is the better choice for that header. These fans' speeds will be controlled according to the temperature measured by a sensor on the mobo.

 

[rage690]

thanks guys. will do

 

[Paperdoc]

Thanks for Best Solution. Enjoy your system!