Check the cable behind the cable booster. Sometimes is loosens up. Also make sure you don't have the booster button turned on. It may be possible that the booster may be bad. Here's a pic of the back of the booster.
Mark & Susan
'13 Cruiser Patriot 335SS - '13 Ford F150 SCREW - PullRite Superslide - Roadmaster Active Suspension Member - "Northeast Adventures RV Rally Group" & "Mason-Dixon Bunch"