A classic problem with using the Casio SK-1 is its auto off function, which will turn off the SK after about 7mins if not touched! MTO have found away around this problem by introducing a timer circuit with an optocoupler, this presses the cancel button every 15 seconds keeping the SK constantly on, here’s our schematic and where to place on the SK-1 circuit board,
MTO SK-1 Auto off defeat drawn
MTO SK-1 Auto off defeat Schematic using a timer and optocoupler.