after being on for one minute cannot change program or set new function only the stop or off works. will not change channels or set new functions only after turning off at mains and starting again,would I then be able set new channel and function, but has to be done in the minute window. the set records and plays back very well, just can't drive it though other commands with out switching off.!??

malc, December 2016

You do not say the make or model of your equipment - but no matter. It clearly (very probably) has a warm-up fault - a component is failing as the temperature increases.

An engineer might be able to track it down by selectively using a freezer spray.

Good Luck..., December 2016