CPU Fan mod

[shadowpr]

Does anyone know how to make a cpu fan with a 4 pin connector plug directly to the power supply, and not let the mb regulate it?

[Cricket]

The 4 pin CPU fan power connector can be used on 3 pin fan headers so you should be able to use the 3 pin to 4 pin molex power adapter.

Cricket

[shadowpr]

Thank you for that.

I have a few 3 pin to 4 pin molex connectors on their way already. Should have oreded one more.

[shadowpr]

I have a little problem. I took the 4 pin connection from my cpu fan, and plugged it into a 3pin to 4 pin molex connection. Then I plugged the molex into the power supply. My fan turns on, and runs, but I get a cpu fan error on the post screen.

Anyway around this?

[Cricket]

The BIOS is expecting a RPM signal from the fan but since a 4 pin molex connector doesn't provide a RPM signal wire the BIOS doesn't get the signal. You might be able to disable that function in the BIOS. If not, does the computer boot up or does it stay stuck on that error message?

Cricket

[shadowpr]

It seems to be stuck on that message. It won't even let me into the bios.

Is it possible for me to take those 4 pins apart, and just connect the one pin to the mb?

[Cricket]

How many wires are coming out of the fan itself? Just two (red and black)? Or three (red, black and yellow)?

They have fans that have a separate RPM sensing wire and a 4 pin molex power connector so you can connect to the power supply but still send the RPM info to the BIOS through the CPU fan header.

Cricket

[shadowpr]

There are 4 coming out of the cpu fan. They are black, yellow, green, and blue.

I'm basically trying to set it up so my Zalman 9500: http://www.newegg.com/Product/Produc...82E16835118003 connects straight to the power supply so that the mb doesn't stop it from running at it's max.

[Cricket]

I'm pretty sure the black and yellow are the power and ground wires...you can double check by noting which wires match up to the power wires on the 3 to 4 pin adapter. The other two wire are probably for RPM monitoring (not quite sure why they came up with the 4 wire CPU fan headers and what the green and blue wires are used for exacty).

Connect the original 4 pin fan connector to the CPU fan header and make note of where each wire is. If you don't mind doing a little wire modding you could cut the green and blue wires and then get a 2 pin connector (if you have any available) and splice the green and blue wires to the appropriate wires coming out of the connector...just be sure those two wires will be connected to the right pins on the CPU fan header.

Of course do this at your own risk. I've done similar in the past but never with a 4 wire CPU fan connector.

Cricket

[Lespaul20]

Thats seems like a lot of jerry rigging. What's reason you need to do it if you don't mind me asking?

[shadowpr]

My temps just weren't loooking right on my oc.

So I suspect that the motherboard is lowering the fan until it gets hot, then ups it to cool it down. That was leading to my temps fluctuating.

[Cricket]

Did you try disabling the temp monitoring/fan RPM function in the BIOS? On some of my ASUS motherboards I can disable that function and just run the fan full speed without temp monitoring.

Cricket

[shadowpr]

I tried that, maybe I didn't save the setting, but as of now, I cut the wires, and got it to run. The power is connected straight to the psu through a molex connection, and I have one wire going towards the mb so it knows I have a fan.

Thanks guys

[Cricket]

Cool, glad it all worked out for you.

Cricket

[shadowpr]

Me too. I'm calling this build Frankestein, cause of all the trouble it's given me with mods.