Service Diagnosis: Controller Diagnostic Light Analysis - Scotsman CME256 Product Manual

Service Diagnosis: Controller Diagnostic Light Analysis

Problem or Symptom Possible Cause
Machine is off
Unit is off & Water
diagnostic light is ON
or BLINKING
Unit is off &
Refrigeration
diagnostic light is ON
or BLINKING
Unit runs and both
Diagnostic lites are
ON
Same, but 1 light is on
* Machine may be reset by pushing and releasing the Off button, then pushing and releasing the
Freeze button. ** See following pages
CME256, 506, 656, 806: AutoIQ™ Cubers
Bin is full, ice in cube port
Power is off, check
controller lights.
Transformer is open
Unit has been switched off
Off lite is glowing
Compressor will not start
Unit has Shut Down
Water inlet valve
malfunction
Water pump malfunction
Water level not sensed or
not high enough
Low discharge or long
freeze cycle
Harvest problem
Hot Gas Valve failure
High Discharge Temp
Harvest problem
Unit does not go into
harvest - exceeds
maximum freeze time
Exceeds maxi harvest time
Temperature sensors out
of range
Reservoir temp. wrong
January 2002
Page 23
Probable Correction
Use some ice
If all lights are out, check power supply,
restore power if off
If all lights are out and there is power, check
transformer output for 24 vac
Push and release Freeze button to restart
unit.
Not enough water or water not sensed.
Check for Refrigeration or Water Error
Check water diagnostic light, if it blinks 2
times and repeats, check the water inlet valve
for proper water flow.**
Check that pump hose is attached and if
pump is plugged in and working.
Check harness from sensor. Check
levelness, check standpipe height.
If the Refrigeration light is glowing steadily,
there is a probable refrigeration problem
If the Refrigeration light blinks once and
repeats, look for a harvest problem.** On
controllers 17-1 and higher, this also indicates
that cubes were "sensed" by the bin controls.
Check hot gas valve operation.
If the refrigeration diagnostic light blinks 3
times and then repeats, check for a reason for
high discharge temperatures.
Controllers 17-1 and higher, if the lite blinks 2
times and repeats, check for a harvest error -
no cubes sensed.
Push and release Off button. Push and
release Freeze button. Check operation.
Push cube size float down and check
operation.
Check for cause of long harvest cycle**
Replace the temperature sensor set (water
and discharge).
Reset and check water temp and sensor.