How to Determine the Xbox 360 Secondary Error Code
When the Xbox 360 encounters a hardware failure it will usually indicate this by displaying 1, 2 or 3 red lights around the power button or in case of Xbox 360S (slim), just the red light in the center of the power button. This is commonly known as the Red Ring of death (RROD), Red Light of Death (RLOD) or Red Dot of Death which are all just different ways to describe the same issue.
If your X360 doesn't turn on and there is a red light indicator, follow these steps to determine your Secondary Error Code (this code should be provided when placing a repair service order):

Here is how to convert the lights into the secondary error code:
1 light = 1
2 lights = 2
3 lights = 3
4 lights = 0
So, for example if you get 4 1 1 4, your error code is 0110, if the lights are 4 1 4 2 then your error code is 0102.
** Please Note: If you have error code 0003, do not order a repair service on this site to fix it. This is usually a power problem, so try replacing the power brick first. If a system is sent in with Error Code 0003 it will be sent back. I do not repair power supplies due to the relatively cheap cost to replace them.