Home Theater Questions? Ask a Technician for Answers ASAP
Hi and welcome to JustAnswer,Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially, have you tried swapping the cable box and the Sony BDP-S5100 Blu-Ray player ? i.e. cable box to the BD HDMI port and Sony BDP-S5100 Blu-Ray player to the SAT/CBL
Offhand, a possibility would be anything "new" added within a week ago. This could be any electronic device that may be radiating interference (RFI) such as (but not limited to) wireless phone, WiFi devices, alarms, electronic lamp ballasts, LAN connected devices or even a new TV or others of the likes.
Proposed preliminary tries (if have not been done):