Sub-Zero Control Board Test Procedure

WARNING! ELECTRICAL SHOCK HAZARD! THESE TESTS MUST BE PERFORMED WITH 115 VOLTS AC SUPPLIED TO UNIT. EVEN WHEN UNIT IS IN OFF MODE, 115 VOLTS AC IS STILL PRESENT AT CONTROL BOARD. USE EXTREME CAUTION WHEN PERFORMING THESE TESTS.

NOTE: This procedure applies to 600 series units starting with serial #1810000 and all 700-2 series tall units.

Tools Needed:
Phillips Screwdriver, Volt Meter

Test Procedure:

1. Switch unit off, then on using UNIT ON/OFF key.
   • (If "- -" does not appear, go to step 2.)
   a. If "- -" appears, compartment has been manually disabled. To re-enable, switch unit off using UNIT ON/OFF key. With unit off, press and hold WARMER key for disabled compartment, press UNIT ON/OFF key, then release keys.
2. Initiate Diagnostic Mode.
   • Press and hold either COLDER key, press UNIT ON/OFF key, then release keys.
   a. If "Sr" does not appear, wait 20 seconds for Diagnostic Mode to end, then go to step 3.
   b. If "Sr" appears, unit is in Showroom Mode. To exit Showroom Mode, wait 20 seconds for Diagnostic Mode to end, then switch unit off using UNIT ON/OFF key. With unit off, press and hold either pair of WARMER and COLDER keys, press UNIT ON/OFF key, then release keys.
3. Switch icemaker off, then on using ICE ON/OFF key.
   • (If no ICE ON/OFF key, go to step 4.)
   a. Check for 115 Volts AC between white and pink wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.
4. Model 601RG ONLY, switch accent lights off, then on using LIGHTS ON/OFF key.
   • (If not model 601 RG, go to step 5.)
   a. Check for 115 Volts AC between white and pink wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board
5. Model 611G or 650G ONLY, switch accent lights off, then on using LIGHTS ON/OFF key.
   • (If not model 611G or 650G, go to step 6.)
   a. Check for 115 Volts AC between white and white/blue wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.
6. Check for 115 Volts AC between white and yellow wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.



NOTE: It is not necessary to remove board or detach wiring from board to perfonv tests. Volt Meter probes will fit into electrical housings. See illustration above, and note wire color order at top of illustration.

7. Initiate Refrigerator Manual Compartment Activation Mode.
   • Press and hold Refrigerator COLDER key and UNIT ON/OFF key until "rE" appears in right display area.
   • Model 700TR-2 Only – press and hold upper Refrigerator COLDER key and UNIT ON/OFF key until "UE" appears in right display area.
   • (If no Refrigerator section, go to step 8.).
   a. All models except 601R, 601RG, 601F and 700TF – Check for 115 Volts AC between white and white/red wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.
   b. All models except 601F and 700TF – Check for 115 Volts AC between white and gray wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.
   с. Models 601RG, 611G and 650G Only – Check for 115 Volts AC between white and red wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.

   NOTE: After voltage checks are completed, exit Manual Compartment Activation mode by switching unit off, then on using UNIT ON/OFF key.

8. Initiate Freezer Manual Compartment Activation Mode.
   • Press and hold Freezer COLDER key and UNIT ON/OFF key until "FE" appears in right display area.
   • Model 700TR-2 Only – press and hold lower Refrigerator COLDER key and UNIT ON/OFF key until "LE" appears in right display area.
   • (If no Freezer section, go to step 9.)
   a. Check for 115 Volts AC between white and purple wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.
   NOTE: After voltage checks are completed, exit Manual Compartment Activation mode by switching unit off, then on using UNIT ON/OFF key
9. Initiate Manual Freezer Evaporator Defrost.
   • Press and hold ICE key for 5 seconds (until ICE annunciator changes state and relay on control board clicks).
   • (If no Freezer, go to step 10.)
   a. Check for 115 Volts AC between white and blue wires. If no 115 Volts AC, check wire connections. If wire connections good, replace control board.

   NOTE: After voltage checks are completed, exit Manual Freezer Evaporator Defrost by switching unit off, then on using UNIT ON/OFF key.

10. If control board passes all preceding tests, do NOT replace board. Refer to troubleshooting guide located behind grille or in service manual for assistance.

NOTE: It is not necessary to remove board or detach wiring from board to perform tests. Volt Meter probes will fit into electrical housings. See illustration above, and note wire color order at top of illustration.

Russ On March 13, 2024   /   Refrigerators, Service manuals   /   Leave a comment