My xbox 360 has the third player light flashing red.

I have had my xbox 360 for under a year and it already has the third player light flashing red. On the screen it says E 74. I was playing it about ten minutes before i turned it on again and got the fashing light.
Ive been told that the problem is that it overheats, or its the a/v cable or its the hard drive. But it was cold and i tried 3 of my friends a/v cables and started the xbox up w/o the hard drive in. none of this helped. I dont know what to do from here, help would be greatly appreciated!!