turn it off at the wall, and tell her she broke it. don't put it back on for a couple of days while she is awak. it will mean you and DH might miss out on something, but make it so that she is aware that it doesn't work. then turn it back on when she's been really good for a while.

it worked with my friends kids - they have a TV that they unplugged cos the kids kept messing with the remotes (took the batteries out first, so one of the kids worked out how to press the buttons on the tv, so it got unplugged) - it might not work for a 14 month old, but it's worth a try