Thread: CPU fan Mod

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    Exclamation CPU fan Mod


    Hi guys I have a MSI Mother Boad which has a function of controling all

    system fans according to system load(fans will spin faster when in

    heavy cpu usage and slower when in idle state).

    I bought Cooler Master's JET 7, for my processor as the default AMD

    fan was not doing its job that well(processor can reach up to 70

    degrees at times).

    The problem now is, the cooler master's jet7 comes with 2 connectors.

    One four pin connector like the power connector for harddisk and stuff

    to power it but only two wires are connected (black GND, Red

    +voltage)and a 3 pin connector with only one wire, which is for fan

    speed detection.

    My mother board can only control the speed of the fan if the power

    cable is fixed to the 3 pin connector as well(as the voltage given to

    the fan is controled by the mother board in the 3 pin connector) And

    should not be drawing fixed voltage directly from the 4 pin connector

    from the powersupply.

    I want to cut the 2 wires from the 4 pin connector(black GND, red

    +Voltage) and connect to the 3 pin connector solving the problem. Now I

    know which wire goes where and how to do it and stuff but all i'm not

    sure is, is it ok to connect the fan's power wires which from the fan's

    data sheet claims to be 13.8V at max speed be connected to the 3 pin

    connector,which I know from the mother boad's user guide which says

    supports fans with 12V.

    Any possibility it may cause any trip and damage my system since the

    fan CAN draw more then 12V at MAX speed?

    Link to the fan's website below:
    http://www.coolermaster.com/index.php?LT=english&Language_s=2&url_place

    =product&p_serial=ACB-V83-U2&other_title=ACB-V83-U2Jet%207%2B
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    Dont worry about letting the motherboard control the fan speed. just connect the 3 pin plug with only the yellow wire to the board so that it know that there its a fan running and connect the other one to the 4 pin connector. myself i dont like for the board to control the fan. id rather let it run full speed all the time. but if you want your should be able to cut the wires and do it the way you want it wont hurt anything but if i was you i wouldn't
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    If you are not shy of soldering I built the following for my systems and it works great. Using in two system, overclocked athlon palomino and dual overclocked celeron.

    http://www.heatsink-guide.com/tempcontrol.htm

    Only side affect is cannot use fans on this with fan monitoring on motherboard. I do not set CPU/Chipset fans to spin down, just case fans, so not a great loss for me. You can use on chipset/cpu fans but cannot use with monitoring lead on motherboard (no great loss, as temperature is more critical to watch than the actual fan speeds, unless case gets dirty and high probability of fans clogging).

    Cheap to make, works great, and is adjustable. It is capable of taking a huge load (more fans than a typical PC would fit).

    Does not answer your question but may eliminate the need for the question. I prefer to attach as few fans to motherboard as possible (especially high watt/mA fans) so this would be my recommendation.

    If you make the circuit I pointed out, I tore apart old power supplies to get heat-sinks for the MOSFETs and the rest of the components are fairly easy to get (radio shack, etc.).

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