Intermittent picture problem on Onkyo 608

Hi all

I have a intermittent problem with my Onkyo 608 av amp, when i installed it to my tv and blu ray player it all worked fine for a while the after a few months i could not get any picture on the tv from all sources, ie sky hd, dvd player and blu ray player. I even changed the hdmi leads around and still no picture. So i by-past the amp and pluged the blu ray player in to the hdmi socket and the picture was fine.

I took the amp back to the AUDIO t and they could not find a fault with it, so i reinstalled it and it all worked fine, then a few months later it did it again, no picture, the menu from the amp works on the tv but it wont play any of the equipment pluged in all i get is a blue picture, its doing my head in as every time you take it out to get it checked you have to unplug all the cables which there are a lot.

I have got some new QED cables from the blu ray to amp and amp to tv and it still have no picture, all the speaker cables seems sound and other leads concted.

I have heard on the forams about hand shake problems with hdmi leads but i dont no what that is.

My home cinema kit is a LG 50PZ990, Sony BD570 and Onkyo 608.

So any advice will be very welcome, thanks