PS3 homescreen either blank or flickering
It probably has to do with the speed of the HDMI cable and the resolution of the home screen vs the resolution of the games. Most games on PS3 run at 720p. The home screen can run up to 1080p. If your HDMI cable doesn't support fast enough bandwidth to sustain a 1080p connection, it would flicker or drop out at the home screen. Try manually configuring your video settings on the PS3 and deselect 1080p as a valid format (1080i or 720p should work fine). That should eliminate the flickering at the home screen without needing to buy a better HDMI cable.