I have had an Xbox 360 since December 2005. It never had any overheating problems.
I recently disassembled my 360; while disassembled (i.e. case bottom removed), it worked fine.
After reassembling it, it IMMEDIATELY (within a few seconds of turning it on) overheated (red lights in quadrants 1 and 3 - i.e. the two left quarters of the circle of lights).
I opened the case up again, to make sure the fans were both running and to look inside in case anything was wrong etc.; I found nothing wrong.
In fact, the console works fine again (no overheating) while the other half of the case is left unattached.
I am sure that it will overheat (red lights flashing in quadrants 1 and 3) again as soon as I reassemble the case again (less room for air to flow), since I haven't changed anything since opening it.
It is currently sitting on a newspaper with a DVD case in the middle, to raise it up a bit, with only the top half of the plastic shell (and the faceplate) attached, so that I can control the DVD eject without the controller.
Both rear fans are operating.
The manufacture date is 11/29/2005
Any suggestions, now that I have it open and can easily access the internals, would be greatly apptreciated.
In the meantime I will research more heatsink posts.
This post has been edited by RacerZ: Aug 20 2006, 08:18 PM