Things You'll Need
Instructions
Try plugging in a different AV cable to be certain that the simplest fix is not overlooked.
Un-solder anything you have added to your console lately. It is possible that the addition is drawing too much power from the system. Ensure that nothing interferes with the GPU's operation.
Tighten the GPU screws that face the HANA chip. Use a shim to tighten the screws a bit more. The shim adds surface area to press against the heat sink, which increases your chances of making the error disappear.
Place your Xbox360 board in the oven to unflex the GPU. Use four balls of foil to lift the board from the oven tray. Bake the board at a low temperature of 140-160 degrees Fahrenheit and ensure that your oven doesn't allow the board to heat above 220 degrees Fahrenheit. Insulate the board using foil and masking tape. Bake the board for at least 90 minutes and allow it to cool for 15 minutes once you turn the oven off.