Green lights. Green lights indicate that the console is powered and operating correctly. The number of green lights indicates how many controllers are connected. One red light. This is the Hardware Failure indicator. It is usually accompanied by an “E74” or similar code displayed on the TV. This is caused by the video scalar chip being damaged. Two red lights. This is an overheating error. If the console becomes too hot, the system will shut down and display this light code. The fans will continue running until the components have been cooled. Three red lights. This is the General Hardware Failure, also known as the Red Ring of Death. This indicates that one or more components have failed, and that the system is no longer operable unless you turn off your console for 24 hours. No error code will be displayed on the TV. Four red lights. This indicates that the AV cable is not correctly plugged in. Check the connection from the console to the TV. This code will not display for HDMI connections.
To fix it yourself, you will need to open the 360 and remove the motherboard from the case. After removing the motherboard, you will remove the heat sinks from the CPU and GPU. They are removed by prying the clamps off the back of the motherboard. After removing the heat sinks, you will need to scrape off the old thermal grease and apply a new layer. You may need to use acetone or nail polish remover to remove the old thermal paste. After removing the thermal paste, you will remove the squishy thermal pads. Replace the heat sinks and the thermal pads with the new parts and reassemble the Xbox.
Excess heat warps the motherboard, separating it from the CPU and GPU chips.
