Sub-Zero UC-24 series Service Manual page 43

Under Counter (UC-24) Series
PROBLEM
(Continued)
F. Warm Refrigerator
Temperatures, "SERVICE"
not displayed or Flashing
G. Refrigerator Temperatures
Too Cold with or without
"SERVICE" Flashing
(Model UC-24C ONLY)
POSSIBLE CAUSE
Evaporator Fan Fault
a. Fan blade obstructed or out of position
b. Evaporator fan motor disconnected
c. Power to Fan Fault, or Fan Motor
Defective
(NOTE: Compressor must be running)
Compartment Thermistor Misread
Air Baffle Control Fault
(Model UC-24C ONLY)
a. Baffle Control Stuck
b. Baffle Control Disconnected, Defective,
or not Receiving Signal from Control
Board.
Evaporator Heavily Frosted
a. Door ajar
b. Evaporator fan fault
c. Compartment thermistor misread
Power to Compressor Fault
Sealed System Fault
• Sealed System Leak
• Sealed System Restriction
• Inefficient Compressor
See Air Baffle Control Fault above
(Under Problem F)
Troubleshooting Guides
a. Move obstruction or reposition blade.
b. Check electrical connections & continuity
from control board to motor. Reconnect /
repair bad connections.
c. With light switch depressed, check for AC
Voltage from control board to fan motor.
Replace control board if defective, or
Replace motor if defective.
Check resistance of refrigerator compart-
ment thermistor for 30,000 to 33,000 ohms
at 32°F (0°C). Replace if defective.
a. Manually open / close air baffle control. If
movement is not smooth, replace baffle con-
trol.
b. With light switch depressed, initiate Manual
Compartment Activation Mode for refrigera-
tor compartment and observe baffle opera-
tion. If baffle does not open within 3 min-
utes:
1. Check electrical connections from baffle
control to control board. Reconnect / repair
bad connections.
2. If electrical connections and wiring are
good, and baffle moves freely, replace con-
trol board.
a. See Door Ajar above.
b. See Evaporator Fan Fault above.
c. See Thermistor Misread above
Check for AC Voltage at control board.
Replace control board if defective.
See Sealed System Troubleshooting Guide
See Air Baffle Control Fault above
(Under Problem F)
8-9
#7003933 - Revision B - November, 2007
TEST / ACTION
Low Voltage Circuit.
Do NOT apply Line
Voltage