When Microsoft designed the 360, they chose a slightly unusual way of mounting the
heat sinks to the processors. When the console is running, there is a tremendous
amount of heat build up inside the case. This causes the motherboard to flex against the
X-Clamp support plastic (see picture 1) which in turn can cause the soldered joints on
the processors to come away from the motherboard itself. This results in the Red Lights
of Death.
Due to the inefficient design of the heat sink clamping method, this is a very large
problem. Although Microsoft havent (as of yet) come up with a decent design fix. On the
latest Elite versions of the console they have used epoxy resin to glue the corners of
the processors down to stop the flexing that causes this error (see picture 2). Whether
their fix will stand the test of time remains to be seen.
What the modification contained in this manual achieves is to alleviate board flexing and
apply uniform pressure to the processors. This uniform pressure is enough to remake
the faulty joints resulting in a working console. Also, because the pressure on the
processors is uniform the heat sinks do a much better job of dissipating the heat build
up.