Lang GCCO-T Service Manual page 52

NO MOTOR, MANUAL MODE
PROBABLE CAUSE
Defective back-up toggle
switch
Defective back-up relay
Defective component
transformer
Defective motor relay
Defective motor
NO MOTOR, COMPUTER MODE
IMPORTANT NOTICE: Before trying to trouble shoot "No Motor in Computer Mode" confirm that motor is
operational in "Manual Mode".
PROBABLE CAUSE
Defective output on CPU
board
TROUBLESHOOTING GCCO-PP / -PT CONT'D
CORRECTIVE ACTION
Confirm that toggle switch is in the "ON" position.
Check toggle switch for normal operation.
Check for 24VAC at relay coil.
If no voltage is present:
Confirm that points are making.
If voltage is present:
Replace relay.
Confirm that 120VAC is feeding primary coil.
Confirm that 24VAC is at secondary coil.
Check for 24VAC at relay coil.
If no voltage is present:
Confirm that points are making.
If voltage is present:
Replace relay.
Check for 120VAC across P1 and T7/T4.
If no voltage is present:
Confirm that wires have continuity.
If voltage is present:
Replace motor.
CORRECTIVE ACTION
Check for 24VAC at JP12 for high or JP13 for low (while oven is
calling for heat).
If no voltage is present:
Board is operating correctly.
If voltage is present:
Replace CPU.
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