Maybe your at a cross-roads right now.  Fix the old Jenn Air downdraft or replace it with something new.  Let me help you with your decision.  First, I am not a repairman, but I have stripped down Jenn Air stoves for 7 years now and have learned a thing or two.  First, the older Jenn Airs are built like tanks (and weigh like one too!)  Parts will wear out over time but most are very fixable with little skill.  The old downdrafts have mostly mechanical parts with little to no computers on board...except for possibly the clock. Compare that to today's ovens which are mostly computer controlled.  If the touchpad goes out, you're in for an expensive fix.  If your computer board gets shorted out, I hope you have the warranty.  Now, looking back at the old downdrafts I can report to you what I've seen fail.  Mostly burner switches, oven element contacts and of course the clocks.  (Usually it's the mechanical clocks that goes first).  All the cartridges and elements are easily replacable.  Not all parts are still available on these 15-25 year old models, but thanks to Ebay, many can still be found.  Jenn Air has done a wonderful job of NOT re-inventing the wheel so some parts will fit multiple models....like the burner switches.  I'm sure the new models are much more energy efficient and probably better for the environment, but I'm all for keeping a good working stove alive.