Problem began when the NORMAL light and STart light would not illuminate when pressed and machine wouldn't start. All other lights work, but machine would not start in HEAVY duty mode. Problem was intermittent and then less than intermittent.
Made educated determination that the electronic control board could be the problem and decided to risk some money on a reconditioned board.
Replaced the board and it ran perfectly for 2 weeks and then the above symptoms reappeared EXACTLY. Both old and new boards show no heat or burn damage.
Have discounted touchpad problems since the new board worked for 2 weeks.

My time is plentiful, but not willing to invest much more money in repairs since new machines are relatively less expesive than 8 years ago.