Schematic (See attached pdf):
Sensors: Speed sensor
And auto-stop sensor. Both are optical. Currently, two comparators are added to control signal.
Main MCU: MSP430G2553.
Motor PWM controller, which generates 1.8v voltage to stabilize speed.
Tonarm shorterer, which pulling down tonarm when Motor is stopped.
Fully compatible with old pcb by dimensions and connections. One-side PCB 125x127mm.