not sure if this goes here, i couldnt find a buy/sell category, apologies if this is in the wrong place...
here is my "Coolmod"
it is a circuit that has a temp control IC on it that will control the speed of the 360 fans dependent on the temperature of the GPU. As the temperature of the GPU increases the thermistor's resistance changes which causes the fans to speed up. The fan will always have a minimum 5V on them to ensure that they spin up when first turning on the 360.
the circuit will work on any 12v fans, be it a 360, xbox, PC etc. The mod comes complete with all wires and there are only 2 wires to solder to the board (12V and Ground).
You simply unplug your fan from the motherboard header and plug it in to the supplied 3 or 4 pin header (your choice). Place the temperature sensor on the GPU heatsink right above the centre of the GPU and the circuit will do the rest. The 12v power is taken directly from the main 12V rail on the motherboard so there is no problem with too much current draw. The mod itself does not get warm (it is able to control another set of fans if desired barely getting warm). This mod will work on all 360's whether hacked or retail. the only difference between the different revisions will be the tapping points for 12V and either a 3 pin or a 4 pin fan connector.
Idling speed of the fans can be altered by controlling a variable resistor which in turn will increase/decrease the idling speed of the fans. Regardless of the idling speed the fans will still be automatically controlled if a higher speed is required due to increased temp. Correct placement of the sensor is important to ensure the correct speed of the fans at a given temperature. I have tested it on 4 360's and had an average drop of 13 deg C. The nice thing is even if you have a 360 that runs cool, you can make it run even cooler without too much increase in fan speed (and noise).
A lot of the xclamped and heat gunned 360's run much warmer than their undisturbed counterparts. if you have a temp guage then measure the temperature of the heat sink and you would probably be surprised. Less heat means less warping, less brittleness and longer life of the components so it pays to keep the system running as cool as possible with the least amount of noise..
I was really surprised when i found my brand new refurbished (oxymoron lol)Falcon that i bought from Futureshop was idling at 63 deg measured on top of the Heatsink so i could imagine another 10 -15 degrees at the top of the chip itself. Just because its new doesnt mean its better, once i put this coolmod on it, it dropped to 49 deg C. with the voltage showing at `7.2V
Here is a picture of the board itself located on a xenon motherboard. The circuit is less than 1" square (2.5cm) and does not interfere with case closing etc. I currently have 40 available for shippng on Thursday (21 Jan 09) if demand is good i will have another 50 available in 2 weeks. Price will be $20 Cdn + actual shipping costs to wherever, I would also need to know whether you want a 3 pin or 4 pin fan connector.
This particular board ran at 62 deg idling and now runs at 51 deg C idling
Message me inf interested