Qm20/Qm30; Diagnosing An Ice Machine That Will Not Run - Manitowoc SM050 Technician's Handbook

QM20/QM30

DIAGNOSING AN ICE MACHINE
THAT WILL NOT RUN
High (line) voltage is applied to the control board
(terminals #8 and #2) at all times. Removing
control board fuse or moving the toggle switch to
OFF will not remove the power supplied to the
control board.
1. Verify primary voltage is supplied to ice machine.
2. Verify that the fuse or circuit breaker is closed.
3. Verify control board fuse is OK. If the power light
functions, the fuse is OK.
4. Verify ICE/OFF/WASH toggle switch functions
properly. A defective toggle switch may keep the
ice machine in the OFF mode.
5. Verify the bin thermostat functions properly. A
defective bin thermostat can falsely indicate a full
bin of ice.
6. Verify low DC voltage is properly grounded. Loose
DC wire connections may intermittently stop the
ice machine.
7. Replace the control board.
8. Be sure steps 1-6 were followed thoroughly.
Intermittent problems are not usually related to
the control board.
134
! Warning
Part Number 8001119 10/19