There are several possible problems, but by far, the most common one is, needless to say, one of heat. The cooling of the CPU was actually fairly well done, they put a heat pipe to draw the heat away from the chip (and thus the mainboard). The problem is that the GPU and its low-profile heatsink sit under the DVD drive, and are given a very narrow channel for air to be pulled acrosss the heatsink by the fans. When the GPU heats up enough, its reflow the solder in the ball grid array slightly, and it can then cause the entire mainboard to flex, largely thanks to the X-shaped brackets that hold the heatsinks down to the chips under the mainboard, with a tension fit that presses up directly underneath those chips. So when the system gets too hot, the combination of loosened solder with a mainboard that flexes from heat causes the GPU or CPU to actually break its connection from the board, resulting in the 3RLOD, with the 0102 error code ("unknown hardware era").CantFaketheFunk said:
(for instructions on how to find the secondary error code and what the others mean, go here [http://www.llamma.com/xbox360/repair/Xbox-360-error-codes.htm].)
These are mistakes that first-year tech students make, not people who are supposed to be GOOD at this sort of thing (namely, people that such a phenominally powerful company as Microsoft is supposed to have working on such expensive hardware). Imagine if any other hardware or software company tried to get away with the kind of crap that Microsoft pulls every damn day. I think Vista is proof that absolutely nothing Microsoft can do will ever alienate their user base under any circumstances.