TechSheet-W11175369-REVA
Tech Sheet FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY Do not discard

FAILURE CODE INDICATIONS PRIMARY, SECONDARY, AND MONITOR INTERLOCK SWITCH CHECKOUT PROCEDURES ACU PCBA PIN VOLTAGE MATRIX

NOTE: Many of the problems listed in the chart below may be solved by power cycling: Unplug microwave oven or disconnect power. After 1 minute, IMPORTANT: Before checking the interlock switches, unplug microwave oven or disconnect power. Be sure to disconnect all of the wires at the switch Check for proper voltage by completing the following steps: plug in microwave oven or reconnect power. being tested before making any continuity readings.

DANGER WARNING Display Likely Failure Recommended Repair Procedure NOTE: The Primary Interlock Switch, Monitor Interlock Switch, and Door Interlock Switch are mounted in door lock switch cradle. All the interlock 1. Unplug microwave oven or disconnect power. 3. Plug in microwave oven or reconnect power, and con rm voltage Condition switches can be indenti ed by the wire colors that are connected to the terminals of the switches. See the chart below for wire color designation. reading. “Enter 2. Connect voltage measurement equipment to the terminals listed clock” Power failure Switch Check By Door Open Door Closed below. (P1-3 and P2-1 are neutral.) 4. Unplug microwave oven or disconnect power. F1E4 Microwave ACU F2E1 PCBA failure After a power failure, “Enter clock” will be ashing. Press CANCEL to end this indication. The colon will appear Primary Interlock 1. Unplug microwave oven or disconnect power. – + NOTE: For 50V and over, the tolerance is +/-15V. For 0V, the tolerance is +/-3V. F4E4 Stuck key failure when in Standby mode. 2. Disconnect the wires at the Primary Interlock Switch. – Monitor Interlock 3. Check from the common terminal (black/brown wires) to the + Abbreviations F8E5 Humidity sensor 1. Unplug microwave oven or disconnect power. 3. Replace all parts and panels before operating. + CL – Cavity Light HF – Hood Fan L – Line Voltage TT – Turntable Motor NFS – Neutral for Switch error 2. Replace ACU PCBA. 4. Plug in microwave oven or reconnect power. Secondary Interlock normally open terminal (black/white wires). – HL – Hood Light N – Neutral Door Interlock 4. Reconnect wires to switch. – Electrical Shock Hazard Electrical Shock Hazard Exhaust air template 1. Unplug microwave oven or disconnect power. 4. Plug in microwave oven or reconnect power. + NOTE: When checking voltage readings on ACU PCBA, connect the grounding test lead of voltmeter to P1-3 and P2-1. Use the positive test lead to detection failure 2. Replace keypad. 1. Unplug microwave oven or disconnect power. probe connectors designated below. Only authorized technicians should Disconnect power before servicing. 3. Replace all parts and panels before operating. 5. If problem persists, refer to “PCBA Pin Voltage 2. Disconnect the wires at the Monitor Interlock Switch. perform diagnostic voltage measurements. Matrix.” 3. Check from the common terminal (white wire) to the normally Replace all parts and panels before After performing voltage measurements, operating. 1. Enter the Diagnostics mode (press CANCEL – 6. Enter the Diagnostics mode (press CANCEL – closed terminal (blue/white wires). MW Oven Running— disconnect power before servicing. CANCEL – START), and then press COOK to CANCEL – START), and then press COOK to 4. Reconnect wires to switch. ACV Readings Failure to do so can result in death or display the humidity sensor reading. If display see if failure code reappears. Failure to follow these instructions can electrical shock. does not show “8891,” continue to Step 2. 1. Unplug microwave oven or disconnect power. result in death or electrical shock. NOTE: There may be a delay (approximately 2. Disconnect the wires at the Secondary Interlock Switch. 2. Unplug microwave oven or disconnect power. 1 minute, 20 seconds) before the F4E4 3. Check from the common terminal (white/blue wires) to the MW Oven Plugged In—Sitting Idle—ACV Readings failure code is displayed. 3. Connect a new humidity sensor to the ACU normally open terminal (blue/blue wires). Hood Fan Motor— PCBA P6 connector. 7. If the F4E4 failure code reappears, unplug 4. Reconnect wires to switch. High microwave oven or disconnect power. Hood Fan Motor— 4. Replace all parts and panels before operating. 1. Unplug microwave oven or disconnect power. High, Door Open 8. Replace ACU PCBA. 2. Disconnect the wires at the Door Interlock Switch. Hood Fan Motor— 5. Plug in microwave oven or reconnect power. 3. Check from the common terminal (blue wire) to the Med-High 9. Replace all parts and panels before operating. Hood Fan Motor— Voltage Measurement Safety Information normally closed terminal (orange wire). Med-High, Door Open Hood Light— Hood Light— 10. Plug in microwave oven or reconnect power. 4. Reconnect wires to switch. Hood Fan Motor— High, Door Open Low, Door Open When performing live voltage measurements, you must do the following: Low Hood Light—Low MW Oven Start Verify the controls are in the off position so that the appliance does not start when energized. 1. Enter the Diagnostics mode (press CANCEL – 5. Replace all parts and panels before operating. (+) Continuity (-) No Continuity Pin Name Wire Color Power On, Power On, Hood Fan Motor— Allow enough space to perform the voltage measurements without obstructions. CANCEL – START), and then press OPTIONS/ Door Closed Door Open Low, Door Open Keep other people a safe distance away from the appliance to prevent potential injury. CLOCK to display the exhaust air temperature 6. Plug in microwave oven or reconnect power. NOTE: These diagrams are not intended to show a complete circuit; they represent the position of switches during “DOOR OPEN” or “DOOR Hood Light—High Always use the proper testing equipment. sensor reading. Verify the sensor temperature CLOSED” (continuity checks only). After voltage measurements, always disconnect power before servicing. reading is at room temperature (typically 50ºF 7. Enter the Diagnostics mode (press CANCEL – to 90ºF [10ºC to 32ºC]) and verify failure code. CANCEL – START), and then press OPTIONS/ NOTE: Interlock, Moniter switches and Door interlock switch cannot be adjusted and all these switches should be replaced if any of them is found to be P1-1 (L) Brown 120 120 120 120 120 120 120 120 120 120 120 120 120 If failure code matches complaint, continue to CLOCK to display the cavity temperature sensor defective. After replacing interlock/monitor switches, reconnect wires to switch and check for continuity. P1-3 (N) White Step 2. reading. Verify the sensor temperature reading. If P2-3 (NFS) White it is still not correct, replace ACU PCBA. P2-2 (Door) Orange 2. Unplug microwave oven or disconnect power. P2-1 (N) Green 8. If failure does not reappear, stop. P4-4 (TT) White 3. Disconnect sensor from ACU PCBA. P4-5 (CL) Red Door Closed Door Open P4-1 (HL) Yellow 0 0 0 0 0 0 0 0 0 0 0 0 0 4. Measure sensor resistance between connector P4-2 (HF-R) Gray pins and con rm reading is between 9.5kW and L (NC) (NO) N (NC) L (NC) (NO) N (NC) P4-3 (HF-Hi) Black 0 120 0 120 0 120 0 120 0 120 0 120 3.6 10.5kW at room temperature. If measurement is P4-6 (HF-Lo) Green not correct, or if a short or open circuit is found, (NO) (NC) P5-4 (NO) P5-2 (NO) (NC) (NO) P5-2 replace sensor. Primary Monitor Secondary P5-4 0 120 0 120 0 120 0 120 0 120 0 120 49 Interlock Interlock Switch Switch Interlock Primary Monitor Secondary Interlock Interlock Interlock Switch Switch Switch Switch 0 0 0 0 0 0 0 0 0 0 0 0 0

PRECAUTIONS TO BE OBSERVED BEFORE (NO) (NC) (NO) (NC) 0 120 0 120 0 120 0 120 0 120 0 120 120 P 2-2 P 2-2 AND DURING SERVICING TO AVOID POSSIBLE Door Door 0 120 0 120 0 120 0 120 0 120 0 120 120 Interlock Interlock EXPOSURE TO EXCESSIVE MICROWAVE ENERGY Switch Switch 0 0 0 0 0 0 0 0 120 120 67 67 2.4

a. Do not operate or allow the oven to be operated with the d. Any defective or misadjusted components in the interlock, monitor, 0 0 120 120 120 120 77 77 0 0 0 0 3.6 door open. door seal, and microwave generation and transmission systems shall be repaired, replaced, or adjusted by procedures described NOT HEATING TROUBLESHOOTING INSTRUCTION 0 0 120 120 68 68 39 39 0 0 0 0 3.7 b. Make the following safety checks on all ovens to be serviced in service manual before the oven is released to the owner. before activating the magnetron or other microwave source, IMPORTANT: High voltage is present at the magnetron and high-voltage capacitor terminals. Avoid direct contact when power is connected to these 0 0 151 151 120 120 77 77 0 0 0 0 3.7 and make repairs as necessary: e. A microwave leakage check to verify compliance with the Federal components to avoid serious injury or possible death. Always be sure that the high-voltage capacitor is discharged before accessing any of these Performance Standard should be performed on each oven prior to components. CONNECTORS ON ACU PCBA 1. Interlock Operation release to the owner. For a no-heat condition, refer to the following step-by-step instructions: 2. Proper Door Closing f. Do not attempt to operate the oven if the door glass is broken. 1. Unplug microwave oven or disconnect power. Check for loose or failed connectors on the ACU PCBA 3. Seal and Sealing Surfaces (Arcing, Wear and Other Damage) (P1, P2, P4). If these check out OK, plug in microwave oven P6 3 2 1 P3 14 13 12 11 10 9 8 7 6 5 4 3 2 1 2. Discharge the high-voltage capacitor. or reconnect power. 4. Damage to or Loosening of Hinges and Latches 3. Disconnect the high-voltage transformer primary windings. Check for ACU PCBA failure. Refer to “ACU PCBA Pin 5. Evidence of Dropping or Abuse Voltage Matrix.” Relay 2 P7 4. Attach the voltmeter leads to the high-voltage transformer primary 9. If the input voltage at the high-voltage transformer primary input c. Before turning on microwave power for any service test or input wires. wires is close to the rating voltage 120 +/-15 VAC, unplug microwave P9 1 inspection within the microwave generating compartments, oven or disconnect power. check the magnetron, waveguide or transmission line, and 5. Plug in microwave oven or reconnect power. 10. Check the power supply components. Refer to the “Component 4903 1 2 NOTE: There are purposely empty cavity for proper alignment, integrity and connections. Tests” section. terminals between each of the numbered 6. Close door and program the microwave oven to operate for 1 2 P11 3 terminals on P1 connector. 30 seconds. High-voltage transformer PCBA 4 7. Press START. High-voltage capacitor 1 2 3 4 5 8. Check the input voltage at the high-voltage transformer primary input wires. If the voltage is not close to the rating voltage 6 120+/-15 VAC, unplug microwave oven or disconnect power. Check the circuitry as follows: Relay 7

4903 8

P1 P4 2 P2 9

1.3 123456 1 1 2 3 10

Measure resistance of the fuse, microswitches, and thermostats. High-voltage diode L N 11 Replace any failed components (refer to the wiring diagram). FOR SERVICE TECHNICIAN’S USE ONLY 11. If the power supply components check out OK, check the Check for loose terminals (refer to the wiring diagram). Check all connection between the magnetron and the high-voltage of the terminals on the main route from the power supply to the transformer. high-voltage transformer. 12. If all of the components check out OK, replace the magnetron. 3 13. Reconnect the high-voltage transformer primary windings.

W11175369A 2 4

FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY FOR SERVICE TECHNICIAN’S USE ONLY

TOUCH PANEL PARTS LAYOUT (NOT TO SCALE) COMPONENT TESTS Components Test/Results

Touch Panel and ACU PCBA Test AB IMPORTANT: HF NTC Thermistor 1. If “NTC SHORT, CALL FOR SERVICE” or “NTC OPEN, CALL FOR SERVICE” scrolls on display, C unplug microwave oven or disconnect power. Power Resistor Unplug microwave oven or disconnect power. Conduct a microwave energy test after performing any tests or 3551 2. Measure resistance: repairs to the microwave oven. Cooling Fan Motor To initiate diagnostic routine: DE Discharge the high-voltage capacitor and remove the lead wires P5 Normal: 10k ohms +/-5% at 77ºF (25ºC) FG from the primary winding of the high-voltage transformer before Check that all wire leads are in the correct positions before 1. Plug in microwave oven or reconnect power and press CANCEL to 3. Open door. The model number will be displayed. X H A. Main fuse (20 amp) M. HF NTC thermistor conducting any of the following tests. operating the microwave oven. 1. Unplug microwave oven or disconnect power. Standby (“:”). W I B. AC line lter board N. ACU PCBA 2. Remove wire leads. 4. Close door. All display segments will be lit. C. Hood fan motor assembly O. Touch panel Remove the lead wires from the related component before Grasp wire connectors when removing the wire leads from 3. Measure resistance: 2. Close door, then press CANCEL – CANCEL – START within V J D. Cavity light P1. Secondary interlock switch conducting any of the following tests. microwave oven parts. 3 seconds. 5. Press indicated keypad for correct display readout and beep. E. Cavity light holder P2. Door interlock switch Normal: 65 ohms/65W K F. Magnetron All operational checks using microwave energy must be done with All testing must be done with an ohmmeter having a sensitivity All display segments will be lit to indicate the Test mode has NOTE: If Cancel is pressed during this diagnostic routine, you will exit G. Magnetron thermostat— Q. Monitor interlock switch the microwave oven loaded with a minimum of 8 oz (250 mL) of of 20,000 ohms per volt DC or greater and powered by at least 1. Unplug microwave oven or disconnect power. been entered. the Test mode. R. Primary interlock switch water in a microwave-safe container. a 9-volt battery. 2. Remove wire leads. opens at 257ºF (125ºC), S. Turntable motor 3. Measure resistance: Key Tables for Test Mode closes at 185ºF (85ºC) T. Hood (cooktop) light H. Power resistor U. Hood (cooktop) light holder Normal: 40 to 60 ohms (approximate) Key Name Function Display Buzzer Key Name Function Display Buzzer I. H.V. capacitor V. Motor capacitor Components Test/Results J. H.V. diode W. Cavity thermostat— Popcorn – key 30 1 beep 2 Cavity Light, Cooling CL TT 1 beep K. H.V. transformer H.V. Transformer 1. Unplug microwave oven or disconnect power. Baked Potato – key 31 1 beep Fan, and Turntable ON L. Cooling fan motor opens at 329°F (165°C), Filament 2. Remove wire leads. Veggie – key 2E 1 beep 3 key 36 1 beep U non-resettable (orange/red wires) 3. Measure resistance: AC Line Filter Board 1. Unplug microwave oven or disconnect power. Keep Warm – key 06 1 beep 4 – key 14 1 beep L X. Humidity sensor Primary 2. Remove wire leads. Reheat – key 24 1 beep 5 key 15 1 beep T M Secondary (white Primary winding: Less than 0.5 ohm (approximate) 3. Measure resistance: Defrost – key 25 1 beep 6 – HL HIGH 1 beep S wire – ground to Secondary winding: 120 ohms (approximate) Soften/Melt – key 29 1 beep N transformer case) Filament winding: 0 ohms Normal: L-IN to L-OUT (coil): Less than 1 ohm; N-IN to N-OUT (coil): Less than 1 ohm Cook Time – key 21 1 beep 7 – R P2 O Primary winding to grounding: Normal: In nite Cook Power – key 22 1 beep Q P1 Magnetron Filament winding to grounding: Normal: In nite Auto Cook Humidity sensor check XXX 1 beep 8 Hood (Cooktop) Kitchen Timer – key 05 1 beep Light ON (High) HL LOW 1 beep H.V. Capacitor 1. Unplug microwave oven or disconnect power. Thermostats NOTE: Refer to “Parts Layout” for opening and closing temperatures. On/Off 9 2. Remove wire leads. 1. Unplug microwave oven or disconnect power. Clock/Options HF NTC Thermistor Hood (Cooktop) HF HIGH 1 beep POWER OUTPUT MEASUREMENT H.V. Diode 3. Measure resistance: Cavity Thermostat 2. Remove wire leads. Start Add 30 Sec Software version check 0 Light ON (Low) Magnetron Thermostat 3. Measure continuity: Kids Menu – The power output of the magnetron can be measured using the following Measure Voltage Turntable Motor Filament terminal: Normal: Less than 1 ohm Snack Menu – Light Vent Fan ON “Voltage Measurement at Power Source” and “Output Test.” Before you Filament to chassis: Normal: In nite Normal: Continuity 1 Cavity Light and Cooling Off/High/Low (High Speed) HF LOW 1 beep perform the test: Motor Capacitor Fan ON Turntable 1. Unplug microwave oven or disconnect power. SCHEMATIC DIAGRAM 4-Speed Fan Vent Fan ON MW 1 beep Make sure that the oven cavity is cool and clean. Humidity Sensor 2. Remove wire leads. Off/On (Low Speed) WH 3. Measure resistance: XXX 1 beep Cancel Check the line voltage at the wall outlet while microwave oven RD Cavity Secondary Magnetron 03.00.00* 1 beep Microwave Oven is operating. See the “Voltage Measurement at Power Source” section. BK Terminal to terminal: Normal: Momentarily indicates several ohms and then gradually returns to In nite. Thermostat Interlock Thermostat key 37 1 beep (1000W), CL, TT, Terminal to case: Normal: In nite Switch key 38 1 beep and CF ON key 03 1 beep Tools Needed Resistor 2 4 BU WH BU WH High Voltage CL 1 beep Hood Exhaust Fan Motor NOTE: Some inexpensive meters may indicate in nite resistance in both directions. L P5-2 Components – 2-cup measuring cup 1. Unplug microwave oven or disconnect power. Thermometer 2. Measure resistance: TT CF Voltmeter/ohmmeter A B BU BU P6-3 BU Magnetron Forward: Normal: Continuity YL YL BU BU P5-1 – key 09 1 beep Reverse: Normal: In nite WH P5-4 RD RD Motor BU BU Red Tube FA – key 04 1 beep Capacitor Black Tube F 1. Unplug microwave oven or disconnect power. AC 120V/125V 60Hz White P6-5 WH Exit Test Mode 2. Remove wire leads. Tab C 3. Measure resistance: POWER CORD Cy WH Monitor Black Tube RD Cx HL Interlock Normal: 2.4k to 3.2k ohms (approximate) LN Switch RD 1. Unplug microwave oven or disconnect power. Cy Golden WH : or xx.xx 1 beep 2. Remove wire leads. Y/G Tab HF White WH 3. Measure resistance: YL/GN Tab BK H.V. * May be higher, depending on software upgrades at time of production. Voltage Measurement at Power Source P5-5 BK Capacitor Normal: Momentarily 0 ohms, then goes to In nite. Cement R CL RD 1. Fill the measuring cup with 2 cups (500 mL) of tap water. 1. Unplug microwave oven or disconnect power. GNP6-2WH Golden 2. Remove the 3-pin connector from the electronic control (P6). BK BK Tab 2. Place in the center of the microwave oven cavity. NOTE: Do not remove the attached resistor which is used for internal resistance calibration. Fuse P6-1 Primary H.V. 3. Operate the microwave oven on high power for 1 minute. 3. Measure resistance across pins 1 and 3 and across pins 2 and 3: Interlock 20AMP L BK Switch H.V. Diode 4. While the microwave oven is operating, measure the line voltage Normal: 2.8k ohms (approximate) at 77ºF (28ºC) +/-18ºF (-10ºC) Door at the power source. See “Measure Voltage” illustration. A. House power supply wall outlet 1 3 P1-1 BR BU Interlock Transformer B. Voltmeter/ohmmeter test leads 1. Unplug microwave oven or disconnect power. P4-2 GY Switch 5. Verify the voltage is constant during microwave oven operation. C. Microwave oven plug 2. Remove wire leads. AC Line Filter P1-3 WH P4-1 YL P4-3 BK P4-6 GN P2-1 GN P2-3 WH If voltage drops below 108V, contact a quali ed electrician to check 3. Measure resistance: P4-4 WH P4-5 RD your electrical supply. OR P2-2 RD High Speed—Normal: Red (R) and Blue (BU) wires: 70 to 100 ohms (approximate); Blue (BU) BK 6. Make note of the voltage while the microwave oven is running and Black (BK) wires: 30 to 60 ohms (approximate) and proceed to the output test. Low Speed—Normal: Red (R) and Blue (BU) wires: 70 to 100 ohms (approximate); Blue (BU) DWG NO.: MU- 147-T (Rev. C) N HL L R HF HF relay CL Door N NFS TTM P6 and White (W) wires: 50 to 80 ohms (approximate) HUM HF relay 4911 33K Sensor 4912 2 No Nc

1

TRIAC CL Relay TT Relay SMPS MW Relay MW TURBO P9 7919 4901 4902 4903 Relay 4913 HF NTC

Output Test HF relay Fuse 68K 33K 4917 1. Fill the measuring cup with 2 cups (500 mL) of 70ºF (21ºC) tap water. PCBA 2. Stir the water with the thermometer to ensure uniform temperature. CONDITION: DOOR OPEN 8. Using the following chart, determine if the output of the microwave Add warm or cool water to bring the water to the correct oven is within the range listed based on the line voltage and wattage SYMBOL NOTES: temperature. rating of the microwave oven. 3. Place the measuring cup in the center of the microwave oven cavity. BK WIRE COLOR P2/P3/P4/P5/P6/P7: CONNECTORS 4. Operate the microwave oven on high power for 1 minute. BK BLACK WH: WHITE BR: BROWN 5. Remove the measuring cup and stir the water with the thermometer P6-1 PIN NO. –1 HL HOOD LAMP C F COOLING FAN MOTOR BK HOOD FAN MOTOR BU BLUE GN: GREEN OR: ORANGE for about 20 seconds. CONNECTOR (COOKTOP LAMP) TT TURNTABLE MOTOR RD: RED YL: YELLOW GY: GRAY 6. Record the temperature of the water. NAME WH HF 7. Refer to the model serial tag on the microwave oven to acquire Water Temperature for Line Voltage and Wattage Rating wattage output rating of the microwave oven. BU YL RD

Voltage 700W 1000W 1200W CL CAVITY LAMP

120V 96ºF to 102ºF 110ºF to 116ºF 124ºF to 130ºF (36ºC to 39ºC) (43ºC to 47ºC) (51ºC to 54ºC)

108V 91ºF to 97ºF 101ºF to 107ºF 111ºF to 117ºF W11175369A (33ºC to 36ºC) (38ºC to 42ºC) (44ºC to 47ºC) NOTE: This sheet contains important Technical Service Data.

W11175369A FOR SERVICE TECHNICIAN ONLY DO NOT REMOVE OR DESTROY ©2017. All rights reserved. 11/17

FOR SERVICE TECHNICIAN’S USE ONLY

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