I would start diagnosing the problem by checking to see if the plastic switch had become misaligned with the underlying control. The part that actually connects to the circuit board is like a nipple and the black cover fits over it.
It it is not the switch, it may be the motor or the wiring. I have an extra seat back motor if you need one.
Thank you for the info. much appreciated-i'm probably going to tackle this next spring it's the least of my priority right now- i got to do other things to the car 1st more important.