LED1:
The Heartbeat LED flashes red to indicate
that the fuse F1 is closed, the electronics is
receiving power, and the software is running
normally.
LED2:
When the green compressor LED is ON, it
indicates that the microprocessor is calling for
the relay to turn ON the compressor.
LED3:
When the green defrost solenoid LED is ON, it
indicates that the microprocessor is calling for
the defrost solenoid to turn ON.
LED4:
When the green condenser fan LED is ON, it
indicates that the microprocessor is calling for
the condenser fan to turn ON.
LED5:
When this green LED is ON, it indicates that
the microprocessor is calling for the BLUE
interior lighting to turn ON.
LED6:
When this green LED is ON, it indicates that
the microprocessor is calling for the white
interior lighting to turn ON.
LED7:
When the green evaporator fan LED is ON, it
indicates that the microprocessor is calling for
the evaporator fan to turn ON.
Table 7.1. LED Diagnostics
The red heart beat
LED is not flashing
Confirm that 120 VAC is being
applied to the control board.
Remove the P1 plug and mea-
sure the resistance across F1. It
should be 0 ohm. Replace the
control if P1 is open.
Table 7.2. LED Troubleshooting
Column Refrigeration Service Manual
63
7.0 Component Operation
7.1 Control
The column products come with a custom designed
control, located in on the interior ceiling of the
product.
7.1.1 Diagnostics
See
. for the control board’s integral
Load LED’s for diagnostic purposes. The LED’s
indicate which loads are in operation.
7.1.2 Troubleshooting
To determine if the control board is operating,
check for the heartbeat LED, it should be flashing.
Check all wire connections to ensure they are
connected without any type of damage If not
flashing, using a multimeter check for power at
connector P1, if no power, trace back to determine
where power is being interrupted. If power is
present, but no heartbeat, integral fuse is probably
open (check fuse for continuity), if open replace
board. To troubleshoot individual components,
check diagnostic LED’s for operation and then
confirm power is available at the corresponding
pins. If the correct power is not available at any of
the pins, with the corresponding LED illuminated,
replace the board.