Diagnose 2 red lights on Xbox 360

xbox_360_two_red.txt

Hold the sync button on the console and press the eject button. This will give you some rapidly 
flashing red lights. Make note of how many quadrants are doing this. Repeat this 3 more times to 
obtain a 4 digit sequence.

Four rapidly flashing quadrants = a numerical 0
Three rapidly flashing quadrants = a numerical 3
Two rapidly flashing quadrants = a numerical 2
One rapidly flashing quadrant = a numerical 1

With the 2 flashing red lights, you will most likely get 0011 (CPU), 0012 (GPU), or 0013 (RAM).

If it's 0013, you'll most likely need a reflow on the two RAM blocks left of the GPU. The other two 
error codes might call for a reflow of the CPU or GPU also, but is probably due to the dried up 
OEM thermal paste.

If you have the 3 flashing red lights, you do the same sequence as above to get an error code 
sequence (most likely 0102, 0020, 0022, 0110, 0021, 0031, or 0103).