Just like the subject reads, my clothes dryer won't shut off. It dries
clothes in the expected length of time, but it just keeps running through
all of it's cycles. I have to open the door or unplug it to stop it. When
the same thing happened about 6 months ago I opened a couple of the panels
and vaccuumed out all the lint and crap, put it back together, and the
problem disappeared. The local appliance parts store thinks I need a new
timer - $85. But before I replace the timer on a hunch, I wanted to solicit
advice from others in this group for other possible causes - specifically
components that I can check or measure, or a method to diagnose the cause so
I would have a better certainty that the timer is indeed the problem

It's a Sears Kenmore model/stock no. 97589210 75892; serial no. ME4409635
purchased in 1995. Natural gas. Lint trap cleaned with each use, and the
vent is free flowing. It's been a great machine and I'd like to keep it
going.
TIA,
M.Paul