i have an xbox 360 elite, owned from new approx 4 years.
worked fine until around a week ago when sudddely no picture or sound through hdmi to tv. I have checked the hdmi cable on a different sdource to tv and works fine, so no problem with cable.
Had xbox apart and replaced the heat compound to heat sinks as wasnt much left and put back together.
On start up power light is on contoller registrers top left, fans tarts up, any suggestions please??
as jay_nar has suggested try the composite plug first and see if you get picture that way. if that still fails it could be the Hanna chip, it could also possibly be the GPU, heck could even be the cpu, who knows without an error code (even with error codes it still sometimes is not specific)
being that the consoles is 4 years it could be on it's way to killing itself.
I have worked on plenty of no video consoles and in most cases it just needs a reflow and it will be good to go.