cant get my hdmi cable to work?

[Oozie]

i guys.i recently purchased a panasoic hdmi dvd recorder and bought a hdmi cable to attach it to my hitachi 37 inch lcd tv.when i hooked up the cable the default pic is on the scart.when i put it onto extension 5 on my tv,the hdmi channel theres nothing.ive had my tv replaced thinking it was that and my dvd recorder checked.it sometimes works then deosnt.its set at 720p?can anyone help as im going insane with this.thank you