guys...need help here..

i'm really pissed off now..one problem after another...

this morning i connect my htpc -> hdmi -> pioneer vsx520 avr -> hdmi -> plasma tv .. everything ok..even watch a movie.. then i shutdown go to work bla bla..

then after work..i came home turn on my htpc.. no display! arghh...tension gua mcm ni..

i direct connect to tv...everything ok..but when go thru my avr .. nothing..tweak here and there also nothing...but got audio...

why? why? i'm jammed...

no...nothing on screen..blank.
its like the signal is not detected by the avr. but, u know when windows finish loading got one sound '' tinggg'' something like that...thats how i know the audio is ok...

i plug in my astro as well to the avr...could that be problem? i tried shut off tv and avr. then turn on again together with htpc..still nothing..