Original Xbox 360 Console - use the Flashing Lights Solution on Xbox.com and choose one of the lights that appear and follow
the steps given.
Xbox 360 S Console - Try the following steps given
Disconnect and reconnect all accessories
Remove the hard drive
Remove the USB flash drives
If the system error message does not display with the hard drive removed, your hard drive may be experiencing a hardware failure. You will need to order a new Xbox 360 Hard drive from the Xbox Online Service Center.
If the steps above do not work you will have to request a repair
If the console starts without having the hard drive inside then it's likely that there is an issue with the hard drive itself. If the console is not turning on and you've checked the wires to make sure everything is secure then it's likely that the issue is
with the console and it will need to be repaired. You will need to start the repair process go visiting this page
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