i got a mates xbox with me atm, turning it on you can hear the flubber animation and then the ms dashboard loads.. (you can hear the ambient sounds in the msdash)
green light is stable (normal) and doesn't flash red or orange or whatever, you can navigate around in the dash (can tell by the sounds made), but whatever i try i cant get any form of display.
the dvd tray ejects fine, even after the msdash has been running for a few minutes..
EVERYTHING appears to work, except for video... lol :/

i've read other posts on this same topic and most appear to be from changing the eeprom to a region that their tvs cannot support.. Like i said before, this box has not been modified, so im confused as to how the eeprom could have been changed..

which leads me to the other explaination, the nvidia gpu ?

I've also read a few posts saying that the gpu can overheat and die due to no passive cooling.

Is there anyway to test if the nvidia gpu is infact fried?

Any other suggestions, things i can try??
oh yeh, and warranty is impossible as my mate OPENED the xbox... unfortunetly

Get the game emchassault and do the gamesave exploit on it. Then you can change the TV region etc.

Take this shit to technical support.

try wiggling the a/v connector in the back? mine's giving me very similar problems, at first I thought it was the cable, until I hooked it up at a friend's place with his cables, and it still did it. could just be a loose connection.