Craig,
Solid red, overheated.
Flashing green, bad bios load.
Flashing red-orange, bad video output
Flashing red-green, system faliure (can be alot of things)
An indicator light that is flashing red indicates that there is an Electrically Erasable Programmable Read Only Memory (EEPROM) error and that Xbox cannot start.
EEPROM is a memory device that does not lose the information programmed to it when power is lost. This is where items such as language setting, video modes, audio modes, and game region are stored.
THINGS TO TRY
1. Remove all discs from the Xbox console.
2. Turn off the Xbox console and leave it off for thirty seconds.
3. Carefully read the Xbox instructional manual that came with the Xbox video game system for instructions about to use and how to position the Xbox console to avoid overheating and other problems.
a. Make sure the Xbox console is not located near a heat source. Heat sources can include TVs, computers, monitors, and other electrical devices.
b. Make sure the vents are not blocked. There are vents on the left and right side, and on the rear of the Xbox console. Make sure each vent has at least six inches of clearance and space for air to circulate. If the Xbox is inside a cabinet, move it to see if this prevents heat problems.
4. After the Xbox console is set, turn it back on and make sure that you see a steady green indicator light on the front.
from [http://forums.overclockers.co.uk/showthread.php?p=15516553|here].
If none of that works, you do want to disassemble it, using [[Topic:Xbox|these guides]] and check your fan. Let us know what works.