Do you have to press buttons hard on a remote?
Even if some of the keys have stopped working or have to be pushed really hard, they can be fixed. The most common problem has to do with the keypad's conductivity with the circuit board. Open up the remote, clean it out, and apply a new coat of conductive paint to get the keys working again.
Why is my TV remote acting weird?
Make sure none of the remote buttons are jammed or stuck. The remote control battery terminals may be dirty. Remove the batteries and clean the remote control terminals with a small solution of alcohol, using a cotton bud or soft cloth, then place the batteries back into the remote control.