1. GE Electronic Refrigeration Diagnostics J1 Connector Page 2-4 J2 Connector Page 5,6 J3 Connector Page 7 BPO encoder diagnostics J4 Connector Page 8 J5 Connector Page 9 J7 Connector Page 10 J8, J9, J11 and J12 Connections Page 11 defrost operation page 12 Inverter compressor page 13 Training and Technical Support Team 15-9-07

3. J1 Connector Thermistors Pin 2 «FF2» Thermistor. Not used on all models. Measure the thermistor resistance by reading between the wire connected to this Pin and the wire connected tp Pin 5. Measure this thermistor voltage by reading between Pin 2 and Pin 5 Voltage should be between 2.8 and 3.5 V DC with a good thermistor. Pin 1 «FF1» Thermistor. Not used on all models. If used, measure thermistor resistance by reading the wire connected to this pin and the wire connected to Pin 5. Measure this thermistor voltage by reading between Pin 1 and Pin 5. Voltage should be between 2.8 and 3.5 V DC with a good thermistor. Pin 3 «FZ» Thermistor. Based on the resistance of this thermistor, the processor on the main board determines when to turn the compressor on or off. Measure thermistor resistance by reading between the wire connected to this pin and the wire connected to Pin 5. Measure this thermistor voltage by reading between Pim 3 and Pin 5. Voltage should be between 2.8 and 3.5 V DC with a good thermistor. Pin 4 Evaporator Thermistor based on resistance of this thermistor, the processor on the main board determines if the heater will come on for defrost and when to terminate defrost Measure thermistor resistance by reading between the wire connected to this Pin and the wire connected to Pin 5. Measure this thermistor voltage by reading between Pin 4 and Pin 5. Voltage should be between 2.8 and 3.5 V DC with a good thermistor. Pin 5. Common connection for thermistors and model select. (+5 V DC) Measure supply voltage for thermistors by reading between this Pin and Pin 3 on connector J4.

4. Thermistor Values 166.8 K -40 120.5 K -31 12.7 K 41 16.3 K 32 21 K 23 27.6 K 14 36.4 K 5 48.4 K -4 65 K -13 88 K -22 Resistance in k ohms Temperature in Degrees F 10 K 50 7.8 K 59 1.2 K 140 1.5 K 131 1.8 K 122 2.2 K 113 2.6 K 104 3.2 K 95 4 K 88 5 K 77 6.2 K 68 Resistance in k ohms Temperature in degrees F

6. J2 Connector Fan Motor Connections Pin 1. Evaporator Fan Tachometer provides feed back from fan motor. This feedback tells the processor what speed the fan motor is running. Check for voltage between Pin 1 and Pin 3. The voltage should be 6.3 V DC. Pin 2. Personality input to the board on some models with a FF fan motor. Pin 3. Common lead to all fan motors. Pin 3 to Pin 8, 13.7 V DC. Pin 4. Evaporator Fan. Pin 4 to Pin 3. Between 4 V DC and 12.4 V DC, +/- 10 %, depending on fan speed. Pin 5. Condenser Fan. Pin 5 to Pin 3. Between 4 V DC and 12.4 V DC, +/- 10 %, depending on fan speed on inverter models, 12.4V DC on non-inverter models. Pin 6. Fresh Food Fan (when used) Pin 6 to Pin 3. Between 4 V DC and 12.4 V DC, +/- 10 %, depending on fan speed. Pin 7. Quick Chill MC Fan (when used). Pin 7 to Pin 3. 13.7 V DC, +/- 10%. Pin 8. Fan power supply. +13.7 V DC. Pin 3 to Pin 8. To test Evaporator fan motor look for 12 volts between pin 3 and pin 8 AND 4,8,or 12 volts between pin 3 and pin 4. To test Condenser fan motor look for 12 volts between pin 3 and pin 8 AND 8or 12 volts between pin 3 and pin 5.

7. J3 Connector Damper motor and Encoder Connections Pins 1 thru 4 are the damper stepper motor connections. Pins 5 thru 10 are the Encoder board connection. J3 Pin 1 to J4 Pin 3, 6 V DC Traveling Voltage or 2.3 V DC standing voltage. J3 Pin 2 to J4 Pin 3, 6 V DC Traveling Voltage or 2.3 VDC standing voltage. J3 Pin 3 to J4 Pin 3, 6 V DC Traveling Voltage or 2.3 V DC standing voltage. J3 Pin 4 to J4 Pin 3, 6 V DC Traveling voltage or 2.3 V DC standing voltage. J3 Pin 10. Double Function Pin Encoder Connection Not on all models or on inverter compressor models used to transmit speed data to compressor inverter module on some models. 1.5 to 3 V DC measured between J3 Pin 10 and J4 Pin 3. J3 Pin 5. Encoder Connection. Not used on all models. J3 Pin 6. Encoder Connection. Not used on all models. J3 Pin 7. Encoder Connection. Not used on all models. J3 Pin 8. Encoder Connection. Not used on all models. J3 Pin 9. Encoder Connection . Not used on all models. See Encoder table on how to diagnose the encoder.

8. J4 Connector FF,FZ, Dispenser, and Quick Chill Drawer Serial Data Communications Connections Pin 2 Dispenser Board, FF,FZ, And Quick Chill Drawer +13V DC Power supply. Pin 1 Dispenser, FF, FZ, And Quick Chill Drawer Data Communications on some models. Pin 4 Dispenser Board Input 1. (Input from the Dispenser Board on some models) Pin 3 Board DC Common Ground. Pin 5 Dispenser Board Input 2 (Input from the Dispenser Board on some models) Some pins might not have a wire connected to them depending upon model features.

9. J5 Connector Quick Chill Drawer Connections – Not used on all models Pin 1. Chiller Drawer Damper Motor Connection 13.7 V DC Pin 1to Pin 2. Pin 2. Chiller Drawer Damper Motor Connection 13.7 V DC Pin 1 to Pin 2. Pin 3. Chiller Drawer Damper Motor Connection 13.7 V DC Pin 3 to Pin 4 Not used on all models. Pin 4. Chiller Drawer Damper Motor Connection 13.7 V DC Pin 3 to Pin 4 Not used on all models. Pin 5. Chiller Drawer Thermistoer Connection. Measure resistance by reading between wires connected tp Pin 5 and Pin 6. Measure voltage by reading between Pin 5 and J 4 Pin 3 Voltage should be 5V DC. Pin 6. Chiller Drawer Thermistor Connection. Measure resistance by reading between wires connected to Pin 5 and Pin 6. Measure voltage by reading between J4 Pin 3 and Pin 6. Voltage should be between 2.8 and 3.5 V DC with a good thermistor. Measure thermistor resistance with the wires disconnected from the board. Measure voltages with the wires connected to the board

10. J7 Connector 120 V AC Outputs and Inputs Pin 9. Neutral Connection to Main Board. Pin 8. Blank. Pin 7. Input FZ Door 120V AC With door open between Pin 7 and Pin 9. Pin 6. Input FF Door 120V CA With the door open between Pin 6 and Pin 9. Pin 5. Output Quick Chill Heater 120V CA measured between Pin 5 and Pin 9. Pin 4. Input for auger from FZ door interlock switch. 120V AC between Pin 4 and Pin 9 with the FZ door closed. Pin 3. Output to dispenser water valve solenoid. 120V AC between Pin 3 and Pin 9 with the FZ Door closed and cradle depressed. Pin 2. Output to cube solenoid with Fz Door closed, cubes selected, and cradle switch depressed, 120V AC between Pin 2 and Pin 9. Pin 1. Output to auger motor. 120V AC between Pin 1 and Pin 9. FZ Door closed, cubes or crushed selected, and switch depressed. J7

11. J8, J9, J11 and J12 Connections 120 VAC input and output connections J8 Output to compressor 120 VAC measured between J8 and J7, Pin 9. J8 J9 Output to Defrost Circuit 120 VAC mesured between J9 and J7, Pin 9. J9 J11 Line in to Board. 120 VAC measured between J11 and J7, Pin 9. J11 J12 Output to Monogram drain pan heater 120 VAC measured between J12 et J7 Pin 9. The pan heater is on only during defrost. J12 J8 J9 J11 J12