I am a long term subscriber of cable TV services, but I recently also subscribed to their internet service. Here are the equipments I have...
Scientific Atlanta Explorer 1840 (Cable Box)
Cisco DPC 3825 (Internet modem)
I noticed that ever since I joined the internet service, My TV screen sometimes get divided into many horizontal lines..(Please see the attached pictures). Intially I thought my SamSung LCD (LN-T4061F) was beginning to breakdown, then I suspected may be the internet signal somehow interferenced with the TV signal.. or may be the cable box was malfunctioning.
TV screen samples
If this problem started happening when the internet was installed, my question for you is how was the internet installed? did you install it yourself? did the technician install it? rogers should be able to measure the signal strength of the box and if its poor signal caused by maybe a splitter gone bad then that could be why. Another thing that could have happened is a cable may have gone bad, or worst case, the set top box has gone bad? i noticed its a Standard definitino set top box, so check the cable connections and make sure its connected to your tv with good quality RCA or S-Video connections instead of the F-Type screw on cable, rogers store also will replace faulty RCA cables as well so try that option two.