I really have model JKP18, but did not see this model listed. It has a digital control screen with touch pad. Time is displayed on the screen but cannot change display using the touch pad. Correct voltage gettint to J1 of control board (both 12v & 4v AC). Is the control board at fault or could there be another problem? Fault code F7 keeps showing up on the display. What does this mean? Thanks for any suggestions.