How to reduce temps by 17 degrees:
The first mod is not for an xbox that is still in the official case: the hdd will not fit inside the case because the fan will be pushing it up. If you have made a custom case for your XBOX with 2cm space between the heatsink and the hdd, then this is a great mod. J The second mod should fit fine in a standard XBOX and reduced the temp of my mobo by 16 degrees!
First Mod:
What you need:
Wire mesh
12V DC 40mm x 40m x 10mm mini cooling fan
Hot glue sticks
Hot Glue Gun
Open up XBOX, on the mobo, there are two heatsinks, the one on the right is the cpu, this is the one we will add a mini fan to. On my V1.0 XBOX, the heatsink on the left has a fan attached to it, on my 1.3 XBOX, there is no fan attached to it. If yours has a fan on the left heatsink, solder the red wire of your mini fan to the red wire of the mini fan that is plugged into the top left of the mobo. The same with the other two wires, yellow to yellow and black to black. Tape these up to prevent shorts when you’re done. If yours doesn’t have a mini fan on the left heatsink, solder some pins to the three holes at the top left of the mobo. There should be a white shape drawn onto the mobo around these 3 holes. This shows you how to connect the fan. (This is where the fan pins would be if you had a fan on the left heatsink.) Then you can plug your mini fan to that.
Take the wire mesh, cut a strip big enough to fold all around the heatsink on the right and touch the plastic base on both sides. Then fold it around the heatsink and use hot glue to attach the ends of this mesh to the plastic base of the heatsink.
Now take the 12V mini cooling fan, hot glue this (facing up so that it draws hot air away from the heatsink and cpu) to the wire mesh on the top of the heatsink.
The reason you should glue the wire mesh to the plastic is because the fan will stick to this, the fan will not stick to the heatsink very well at all. You must glue the mesh to the plastic base of the heatsink, not the metal, this also gives a stronger connection.
Done!
(That was the first mod.)