M2 Antenna Systems RC2800PRKX2SU Manual page 23

TROUBLE SHOOTING CONTINUED
TROUBLE SHOOTING CONTINUED.....
SYMPTOM: Positioner runs immediately after control unit is turned on:
POSSIBLE CAUSES:
This can mean that one of your motor control wires on terminal #1 or #2 are grounded. When one of your motor
wires is grounded it completes the path to one side of the power supply. The microprocessor normally turns on
the motor drive chip that in turn, turns on the hexfet that closes the circuit to ground and powers the motor. To
test this, remove the motor wire from terminal #1. Using your ohm meter, see if this wire is shorted to ground. If
not, then the problem may be in the control unit. The hexfet could be shorted or the motor drive chip could have
failed, allowing 10 volts to appear on the gate of the hexfet, turning it on all the time. To confirm that the control
unit is faulty, remove the motor wires. Using your volt meter, measure from terminal #1 to #2. 35 to 45 VDC will
be present on Azimuth and Elevation units while, 24 to 28 VDC will be present on the Polarity Unit. If the control
unit is faulty, Place a call to M2 for an RA (Return Authorization) number so we can be ready for your unit
when it arrives.
Send it to:
M2 Antenna Systems Inc.
4402 N. Selland Ave
Fresno, CA 93722