just the other day i was using my xbox on my tv using an hdmi plugin. It was working fine for 6 months, then i took it to my girlfriends house (has the same tv) and the the tv kept saying no signal. so i brushed it off and thought nothing of it untill i got home later that night and found the xbox was doing the same thing on my tv.
i went through all the troubleshoots (different hdmi cord, hold y+rt when powering up, change network setting, blind change the aspect ratio) and nothing worked. I then tried my laptop with the same hdmi cord and it worked fine and i also tried the xbox with the hdmi on my girlfriends parents tv and it worked fine too. its real frustrating because i would understand if it was just my tv but it also wasnt working on my girlfriends tv (which is the same)... which is weird.
any help would be much apprectiated. also the av jacks work fine in both tvs but i like my hd :p