The most common and irriatable problem with the 360s is of course the 3 red light issue :twisted: . This happens so often that Microsoft had to put a specific extended warranty on it for 3 years! So of course if you have this its a free repair as of right now but we'll go ahead and help you with it as best we can before you call 18004myxbox.
This issue is a hardware failure, and can be linked to many things internal and external on the console, including...
-Console overheating
-Problem with the power supply cord
-Using a non-liscensed microsoft product (cooling fans)
-Internal failure
-Your console failing to read the hard drive
To troubleshoot this you will need to first unplug and replug the av and power cords. Dettach the Hard Drive, and turn the console on. If it works it is having issues with reading the HD, if it doesnt check the light on the power supply brick while the console is on. That light should be green if its any other color the problem is with the Power supply. Either way it needs a repair so go ahead and call in.
There have been rumors of a towel trick working but i do advise that this can actually void your warranty since it had led to melting of important chips within the console. I advise you get it repaired and over with