Remote will not turn off receiver or tv

We have had the receiver and TV for years. The remote worked the TV and receiver until recently. I have tried following the directions on the website and those on the TV screen. I have used every code given. Several will work in controlling the volume and TV input. However, it will not cut off the TV. I will not turn off the receiver. I have the switch on Directv at the top. Not sure why it has just suddenly stopped working. I appreciate your time and help with this matter.