Factual error: Sue's birthday isn't actually on Leap Day as this birthday is her 15th (in season 4 she celebrates her Sweet 16) and Leap Day birthdays are multiples of 4. The closest leap day birthday in this sense would be her 16th.
Factual error: Even if the cable was out at the grandparents' house due to them getting rid of it, the TV itself should still turn on. Access or no access to cable does not dictate whether a TV can be turned on or not.