So, this here 360 sat dead in my closet for a good year, and while cleaning the other day decided to figure out what exactly was wrong with it.
I was getting an almost RROD, only 2 red lights though. Thankfully all that meant was overheating. After tearing it apart, I noticed for some reason I neglected to reinstall the fans. After digging around in my basement, I found the old fan assembly, with a seized fan.
The pieces finally fit back together
I recently gutted my old Sparc Server (E350 or 450, not really sure), and one of the bright spots was that it was sporting 6 120mm fans
NMB brand, 12v .78 amps. They move a ton of air, but you can also hear one running two rooms away. Not really a problem though
With the 360 in pieces I set the fan right over the heatsinks. Normally it would run about 10min before crapping out, with the addition of the fan it lasted a good 30. However even from a completely cold boot, doing anything other than looking at the home screen would result in the system almost immediately shutting down.
Tearing through the basement a bit more, I found a nearly empty tube of AS5, thankfully it was just enough.
I tore the X-clamps off, and found the WORST factory thermal paste job ever. There was hardly anything between the die and the heatsink, it all oozed out and was just stuck to the chip next to the die.
After a through cleaning with some alcohol, q-tips and a razor blade, I put the AS5 on and re-mounted the heatsinks.
I let the system run Gears 2 for a few hours and not a single stutter. Then came the issue of how exactly to mount the fan. I'll let the picture explain itself
For now the fan wire just runs out one of the vents and plugs into an old 12v wall wort I had laying around. I was just going to hook the fan up to the existing header, but the system did not want to power the fan without a sensor wire, and I did not know how I felt letting the 360 control the fan.
When I feel the urge to tear the system apart again, I'm just going to tie the fan directly to the 12v line coming from the 360's PSU. At least then I won't have to unplug the fan myself