If your Xbox begins to overheat, turn the power off and allow it to cool for at least an hour before continuing play. To keep your Xbox 360 S from being affected by the RROD, keep it in a well-ventilated area and make sure the cooling vents are free from obstruction. There are various fixes for the RROD, which include replacing the high-stress x-clamp, reflowing the GPU's solder connection, and also replacing the heat sink in older models with Microsoft's updated Zephyr heat sink. A flaw in the design of the heat sink allows the motherboard to warp in the area around the chip, which causes the chip to lose contact with the board. The most common issue is a cracked or cold solder joint underneath the GPU on the motherboard.
Most, if not all, three-light errors in Xbox 360 S consoles are related to overheating. The error message is not displayed directly, since the console doesn't power on, but it is possible to obtain the secondary error code from the Xbox. A general hardware malfunction has occurred, affecting one or more components. The 'Red Ring of Death' has occurred when all but the top right corner of the light ring are flashing red.
Three red lights (AKA 'Red Ring of Death')