hdmi no picture on apple tv

Has anyone had an issue with apple tvs producing sound but no picture over apple tv's?
I have tried 10 other devices thru my reciever and all work just fine over hdmi.
But both of my apple tv's do not.
Any Ideas?
I can give details but in a nutshell that is the problem. Both of the apple tvs work over component but not hdmi.
Also does anyone know what revision of hdmi that apple is using ? 1.2 1.3? 1.3a?
Message was edited by: mechanic43

Message was edited by: mechanic43