For 5200 model:
Step 1 ground parking brake wire
Step 2 press "4 square" (menu) button on left side of screen
Step 3 touch AV (lower screen)
Step 4 touch "source OFF "
Step 5 touch quadrant 4 (half inch in and half inch up from left lower corner of touch screen) hold your finger there for about 10-12 seconds, "set on" icon will appear
Step 6 touch "set on" and you are done.