Before you buy a new touch pad, take apart the control panel. Remove the board assembly and reconnect the cable. Now test each switch. If it all works, you have a touch pad issue. My bet it will be the switches. It is apparent that over time the internal contacts of the switch get a non conductive coating and no longer work. BTW, the switching mechanism is a tiny disc.
I had a few switches that were dead and replaced them all. I'm skilled in electronics devices and soldering so it was NBD for me. If you are not, you could buy the parts and find a local geek to do the work.