I have been told that so many 360's where sent out without testing. The console heats up and the delicate soldering on some of the chips loosen up and when the console is moved the chips come away from the board and some of the pins no longer make contact. You can place the console horizontal and wrap a couple of bath towels around it and leave it switched on for a couple of hours. If you are lucky the chips will reseat themslves. DO NOT leave the console as it could cause a risk of fire. Getting your console Flashed does not cause this problem, it is a cock up by microsoft who rushed out the consoles untested. Returning your console to microsoft regardless of age for repair is your best and safest bet. They will replace the whole board and return it to you working.
Good luck
The Oracle
December 2008
Yep, this is commonly known as the 'red ring of death'! It means your xbox is knackered basically. As DBG said, it's usually overheating, but ours also did it when my cousins daughter accidently kicked the CD tray! Take it to where you bought it from and they will either repair it or give you a replacement.
Scott
November 2008
The main problem with the 360 is the GPU (graphics chip) overheats and the current console architecture cannot cope with the removal of this (despite those noisy fans). This results in your 3 red light problem and shutdown. Get in contact with Microsoft and they will help you but it will take time. Or contact www.skprepair.co.uk and they can fix your problem.
DBG
November 2008
I can answer this question...
why does my x-box 360 keep goin to the red lights?