What does one bottom right red quadrant mean on an xbox 360?

Answer 1

This is taken from http://editorials.teamxbox.com/xbox/1651/The-Red-Ring-of-Death/p1/

It's a whole page about dealing with the red ring, but also has a nice breakdown of what each quadrent represents.

"Each division turning red indicates a separate problem, all with a different way of resolving the issue...

If all of the lights but the first section are flashing, this means a general hardware failure has occurred. There is little to be done other than trying to unhook and reattach your cables. This problem is a sure sign a visit to the repair center is in your console's future. If the problem is indicated in the second quadrant of the system, it is merely overheating. As too many hours of GRAW will do that to a unit, the proposed cure here is to unplug the unit from the power supply, let it sit to cool down, and perhaps begin scouting for a better location to store your precious investment.

A problem indicated in the third quadrant of the Xbox 360 ring of light is diagnosed as a hardware failure. Once again, try re-inserting all of your cords and cables, but this problem should definitely be dealt with by the repair center. If all four lights are flashing on the front of your console, this is perhaps the easiest problem to fix. This is an issue with the AV cable not being properly inserted into the back of the console. The cure? Just make sure the cord "clicks" once it has been inserted into the unit. If that doesn't work, of course call the repair center, but the four lights are the easiest of the problems to rectify."

Best of luck!