Instructions
One Light is Flashing --- Hardware Problem
Turn off and unplug your Xbox 360.
Unplug all controllers, peripherals and power wires from your Xbox 360.
Plug everything back into your Xbox 360 and turn on your system.
Turn off your Xbox 360 and remove the hard drive if the problem persists.
Turn on your Xbox with the hard drive still unattached. If your game system starts normally, your hard drive is defective and should either be replaced or repaired.
Power down your Xbox 360 and remove all memory sticks if your system continues to display one flashing light when you turn it on.
Press the power button to turn on your Xbox 360. If your game system starts normally, your memory stick should be replaced.
Send your Xbox into the manufacturer for repairs if none of the above troubleshooting tips have helped.
Two Lights are Flashing --- Overheating
Turn off your Xbox and disconnect the power supply.
Move your game console to a cool ventilated place and let it cool down for one hour.
Hook all components back up to your Xbox and turn it on. If the problem persists, contact the manufacturer.
Three Lights are Flashing --- Possible System Failure
Turn off you game console.
Disconnect the power supply from your Xbox 360.
Remove the power supply plug from the socket.
Plug the power supply back in and reconnect the power to your Xbox.
Turn on your game system and check the front panel. If you continue to have three red lights flashing at startup, contact the manufacturer for replacement or repairs.