As there are so many Xbox 360's around and myths about repairing the RROD, I'm going to make a guide about the best way (in my experience) of fixing this common problem.
Towel trick - This is probably one of the most famous myths of repairing a 360.
Good point: you don't have to open the case and ruin the Security seal and the Xbox can still be sent back to Microsoft for repair.
Bad point: Totally crap way of repairing - not very effective and if you're lucky and it does work, it won't last long before the RROD comes back.
Why do we get the RROD?
In a nutshell, the 360 is a poor design and the fans aren't of a very good quality. On heavy graphic rendering games, such as COD4 the GPU (Graphics Processor Unit) becomes VERY hot. The heatsink is directly under the DVD player and is held onto the mainboard with a so called X-clamp. These are flimsy peices of metal and after a while they have a tendency to distort with the heat generated by the GPU. With all this heat and vibrations from the DVD, fans etc - some of the soldered joints on the GPU fails causing the RROD, or E74.
As the CPU (Central Processing Unit) has a much larger and more efficient heatsink, this rarely fails.
The towel trick is partially correct, because the GPU needs to be heated to such an extent, the solder is melted creating a circuit once again, but with the towel trick, the whole Xbox is heated. The CPU has a thermostat built into it so when it overheats, it shuts the console down before the heat can do it's job.
I've got an Xbox coming over soon for a repair so will make a guide for my method of fixing it.
Items required:
T8 torx bit
T10 torx bit
thin bladed electrical screwdriver
Nail varnish remover
Arctic silver thermal paste
M5x10 screws -Qty 8
M5 washers - Qty 24
Talismoon Whisper fan
Time to do repair - around 2 hours
THIS WAS COPYED FROM MY FELLOW SCOOBY PAL OFF ANOTHER FORUM. AS U CAN TELL, HE REPAIRS XBOXES THOUGHT YOU MAY ALL FIND THE READ INTERESTING.