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Troubleshooting
Control Diagnostics Using Temperature Display
The temperature display has a self-diagnosis mode* that can be accessed and will help the technician to test
certain functions of the temperature display, defrost heater, damper, and interior fans. This mode can aid the
service technician in quickly identifying failed or improper operation of certain components and systems.
Control diagnostics using the display does not use error codes to identify problems. Instead, the temperature
display allows access to components or systems to be checked if a problem is detected.
The temperature display must be in an active mode before entering the self-diagnosis test. If the display is
blank, press any temperature button once, then release it. The display will show actual temperatures.
Enter the diagnostic mode by pressing both the freezer temperature (
COLDER
and
WARMER
) pads and
the refrigerator temperature (
COLDER
and
WARMER
) pads simultaneously. All 4 pads must be held for
approximately 3 seconds. Blinking "
00
"s in both the freezer and refrigerator sections of the display indicate
the refrigerator has entered the test mode. Remove
fi
ngers within 5 seconds and press any pad to lock-in
the test mode. The blinking "
00
"s will change over to solid (non-blinking) "
0
"s when the test mode is locked-
in. Failure to lock-in the test mode within 30 seconds will time out the test and return the refrigerator to the
normal cooling mode.
* Not all test modes apply to all models.
FZ
Display
FF
Display
Mode
Comments
0
1
Showroom Mode
When activated, a tone will sound brie
fl
y and the display
will
fl
ash 1 time. The cooling system stops operation. All
HMI functions will operate normally.
0
2
Display Combined HMI
Software Version
Temperature to main controls communications test. A
coded software version is displayed. Dispenser model
will show 2 numbers.
See Note 1
. Internal display model
will test for Pass/Fail. Should show "
P
". If the format is
violated, the display will read "
99
".
0
3
Display Main Control
Software Version
Temperature to dispenser communications test. A coded
software version is displayed. Dispenser model will show
2 numbers.
See Note 1
. Internal display model will show
"
F
" (no dispenser board). If the format is violated, the
display will read "99".
0
4
Combined HMI to Main
communications
Dispenser to main controls communications test.
Dispenser model will test for Pass/Fail. Should show "
P
".
Internal display will show "
F
" (no dispenser board).
0
6
HMI Self Test
Illuminates all LEDs and numerical segments. FF and FZ
displays will initially display "
88
". Pressing temperature
pads will change initial display. Remaining pads pressed
will toggle the LED associated with that pad. Filter pad
repeatedly pressed will toggle red, green, and amber
LEDs. To exit HMI Self Test, press and hold both FF
temperature pads simultaneously for 3 seconds, then
release. (Exits test mode)
0
7
Sensor Self Test
Checks each thermistor in order and displays "P" for
pass, "0" for open circuit, or "S" for shorted circuit.
See
Note 2
.
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Continued next page
)
