However I decided I'd try to avoid this happening in future by improving the cooling of the unit. I did not want to open the 360 as this will void the warranty, which still has 2 years to go. I looked at commercial 360 coolers, and these seem to fall into 3 groups :
1) Bolt on fans at the back of the 360
2) A fan base unit. basically a stand that the 360 sits on in it's vertical mode. The base of the stand has a fan which blows cool air up through the holes in the base/right side of the 360
3) Using a commercial laptop cooler
Of these I didn't really fancy any 1) Bolting additional fans on where existing fans are already desperately trying to vent hot air seems a bad idea to me. The lamina flow of air around propellers is a complex science. Fitting two fans back-to-back does not seem to me to guarantee double the air flow. The fluid dynamics of air flow around fast rotating fans of different size and rotational speed seems haphazard at best. Worse it may actually reduce the air flow . Also if the external fan fails, its blades will block the existing fans exhaust route.
2) Is a better idea as it blows air in to the inside using the holes provided by the design. However this only works if your Xbox in in vertical mode, which is not ideal for where my Sons Xbox is placed.
3) Seems a good idea and some laptop coolers can run using the power from a spare USB port, which the 360 has. However most seem to be too noisy. The 360 fans are already quite loud, so adding more fan noise seems not ideal. These start at around �20 (UK sterling).
I decided to build a homemade, DIY xbox 360 cooler from junk I had lying around.
The "Brick"
First off lets consider the power supply or "brick".

I also periodically blast some air-duster through the vent holes in an attempt to clear any dust that may have accumulated internally. I once had a PC where the core CPU temperature was reduced by 10 degrees just by clearing dust "bunnies" from between the heat sink vanes.
The Base Unit
I decided that the base unit should be placed on a flat metal surface. When placed in the horizontal orientation, the feet of the Xbox keep it only a few millimetres off the ground. While the primary inlet holes for air are at the sides, there are a few holes underneath toward the edges. A certain amount of heat will be conducted through the case work. Placing the unit on a soft insulating surface .i.e. on a carpeted floor would seem a bad idea as air flow would be compromised and case heat would be insulated, and not conducted away into another surface.
I found a black metal shelf from some bedroom clothes rails units we had once used. These are steel shelves with a 10mm overhanging lip along each edge. I'd guess any box section shelving would do.
Next I drilled some vent holes in the metal - along both ends where the console end piece sit and a cluster beneath the centre of the unit. This is to encourage airflow.
It then occurred to me that I had a number of discarded fans from various PC's I've had or worked on. I fitted a case fan vertically on one side of the 360 so it would be blowing into the right had side of the Xbox, where there are small
I also found a smaller fan, the kind sometimes used on older 486 processors or Northbridge chipset coolers. This was thin enough to fit under the shelf, without sitting proud of the edge supports. If it did you could fit some deep rubber feet to raise the whole shelf up further. I glued this beneath the central cluster of holes I'd drilled, using 2 part epoxy glue.
I fitted a small electrical junction box and wired both fans in parallel to the supply. The case fan was whisper quiet but the small "whizzer" was very loud. I read a few posts on the web suggesting putting a 100 Ohm 3 watt resistor in series to drop the voltage further. I didn't have such a thing to hand but had a bunch (9) of 1.1K ohm 1/2 watt resistors which I soldered in parallel with each other giving me a 4 watt resistor of approx 100 Ohms resistance (See adding resistors in parallel ). I wired the composite resistor in series with the small whizzer fan. I tried fitting it in series with both fans but this caused the voltage to drop too low for the large fan to spin at all. In series with the smaller fan was just right. It turns at a slower quieter speed as does the side case fan.
the end result is :
1) I don't obstruct any of the existing cooling fans
2) I can run the Xbox on it's side, which is more space efficient for me
3) It's inaudible when running
4) It cost me nothing
5) It's not too conspicuous
NOTE :Never attempt this or anything similar unless you have a good understanding of electrical safety.
23rd December 2008
Well yesterday my Son reported that the Xbox360 was refusing to boot and the power supply brick displayed a solid red light. We spoke to Microsoft support , and tried a friends power supply, but with the same result. This indicates that while the bricks display the error, the problem is actually with the Xbox itself. The unit will be shipped back to Microsoft for repair. Actually their support were very good I thought, and the whole process is quite click. I had to pay this time as I'm outside the 3 year warranty, so charge was �60. It was a bad time to fail as my Son got Call of Duty 5 for Xmas for the 360, but it will be like a second Christmas when the unit comes back.
7th January 2009
Well the 360 came back from being fixed/replaced by Microsoft and is running again fine. I think it is probably a new base unit, I should have noted down some distinguishing ID numbers.
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