my stock xbox has this problem here how i check, try hdmi on my tv no signal. use same hdmi cable and port on tv connect ps3 works fine, take same cable to parents connect to there tv works fine.
i have no clue what causes it but, i just use the vga cable on hd settings for now. looking to get another box soon.
i have no clue what causes it but, i just use the vga cable on hd settings for now. looking to get another box soon.

