I've tried three hdmi cables between the amp amp and the PJ no joy.
I got the PJ on ebay for £57, only 20 hours lamp use
I've got the HD70 ceiling mounted now and wired via a 25m HDMI 2 cable directly to my ps3 an have a very good picture , once I set the ps3 to output 720P.
I spoke to the Yamaha technical support line and they advised turning off a "monitor check" setting , which apparently inspects the device to see if it can support the resolution, but unfortunately that didn't work either. They did also say it could be the EDID signal and not handshaking successfully and suggested buying an EDID manager , which I've done , just awaiting delivery, but the seller wasn't sure if the cable length would be an issue , can't understand why if the cable carries the signal ok now ?