Trouble with TWC Cicsco 8640HDC and 720p

[rschildt]

I've always had my Cisco cable box set to display all the available HD formats (480 i/p, 720p & 1080i) and never had a problem.  Starting last night, it appears that any channel using 720p is "flickering".  I thought at first it might just be the HDTV signal, but it picture is fine on HDHomerun Prime that has a cablecard.

If I go into the Cisco menu, and disable the 720p on the Output Resolution screen of the High Definition menu, everything is fine.  Possibly the box is going bad?  Or something else?

[LoadStar]

Bad HDMI cable?

[Jack 1000]

Bad HDMI cable?

I agree,

With everything off, try a new HDMI cable.  Unplug box with everything off.  Connect new HDMI cable with everything off.  If issue comes back, set up a service call to check signal and line levels, as well as cable strength.

Jack