I have a 1.4 Xbox. I've installed the X3 in it and when I first turn it on, in either mod chip or no modchip mode, it will boot. However after about 1 min the screen goes blocky, and everything is frozen. I then shut it off. After turning it off if I try starting it all I get is fragging. If I leave it for an hour or so it boots fine again, but then locks up again... I've tried resoldering, and I can't see anything wrong. I've also tried a different X3 and had the same problem.