Did you get this figured out Ju? I hate handshake issues as they are probably one of the more difficult things to diagnose. It does sound like you are attacking the problem correctly though.
May I assume that your ChannelMaster is outputting 720P but you are outputting 1080P from your PS3?Good day everyone,
I'm having an HDMI PS3 to Anthem MRX300 to Epson 8500UB handshaking issue when connected to our in-wall HDMI keystone adapter. No issues with my Channel Master CM7400to Anthem MRX300 to Epson 8500UB
Bypassing the output keystone all together does the trick, however, the handshaking process is not perfect.
HDMI cables have been swapped/replaced from the input end. On the Output side I'm using Dayton 25ft Flat from PartsExpress.
Any suggestions? Cable Replacing?