thx for reply,
no its not jtagged, its the console from my brother (dash 8955) , e74 comes from a bad videocable i think cause his 2nd xbox got it too. (its a 3rd manufactor vga-cable)
i use the headgun without the mobo in case and without gpu cooler (
http://i.ytimg.com/vi/j-Eyz0sOKR4/0.jpg) <- like this .
when i unplug the fan from gpu and let it overheat and cool down it works.
the problem is that the xbox only got e74 if i not play every day. takes about 5days without playing to get e74.
if i play every day it runs perfect.