I have a E74 error, but when i turn it on without the AV cable i get the 4 red rings.
My mate who has the E74 as well, always has it regardless of whether the cable is plugged in or not.
Could it possibly be that my cable is screwed up and not the 360 ?
e74 is a problim with the video things that r ivolved r bad cable
gpu & the chip right behined the gpu if it is the gpu over heat it and aply xclamp