Hi, I need some help here. My Aunt uses a Pronto M17 sure step with a Invacare controller that has Mk6ispj and W/pss written on it. The unit works fine but wont turn off and has trouble turning on as well. I opened it up and tried to clean the buttons but it made no difference. Any one know what it could be? Any simple fix? Thanks

The Mk6 spj w/pss has an overlay with buttons over the sensors. The functionality is very much like a microwave keypad. These buttons go bad over time and you can replace the overlay for under $20. When you press the buttons they contact some inductive sensors on a circuit board underneath which induces a current flow in the sensor. The pads flatten out over time and dirt, oil and food can accumulate under the pads between the pad and sensor. This causes decreased sensitivity and poor function of the buttons. You may be able to carefully remove the overlay and clean it and the underlying circuit board with spray electronic cleaner. This works for awhile, but I usually just replace the overlay. The new overlay comes with a new layer of adhesive. Hope this helps.