Jon - I am an engineer (Electrical/Electronic, in USA) and my girlfriend has a Nordictrack EXP1000 that just experienced sudden stop issue twice in her most recent workout. Treading along at 3.0 mph and sudden stop, as if STOP was pressed. The display still worked (normal), she could restart it again without a power cycle and it happened again some minutes later. I read on another side that the Stop switch can get compromised by sweat and or repeated actuation (most used button?) that is can be temperamental (oxidized/work contacts), and with vibration of machine, can "trip" on its own and cause a sudden stop. This "theory" makes sense, but these can be complex issues. Any experience here? Do you have, or know where I can get, a service manual or schematic wiring diagram for such a machine? Much appreciated.