TechSheet-W10844814-RevA
Tech Sheet FOR SERVICE TECHNICIAN’S USE ONLY Do not discard

DANGER WARNING

Electrical Shock Hazard Electrical Shock Hazard

Only authorized technicians should Disconnect power before servicing. perform diagnostic voltage measurements. Replace all parts and panels before After performing voltage measurements, operating. disconnect power before servicing. Failure to do so can result in death or Failure to follow these instructions can electrical shock. result in death or electrical shock.

Voltage Measurement Safety Information

When performing live voltage measurements, you must do the following: I Verify the controls are in the off position so that the appliance does not start when energized. I Allow enough space to perform the voltage measurements without obstructions. I Keep other people a safe distance away from the appliance to prevent potential injury. I Always use the proper testing equipment. I After voltage measurements, always disconnect power before servicing.

PRECAUTIONS TO BE OBSERVED BEFORE

AND DURING SERVICING TO AVOID POSSIBLE

EXPOSURE TO EXCESSIVE MICROWAVE ENERGY

a. Do not operate or allow the oven to be operated with the door d. Any defective or misadjusted components in the interlock, open. monitor, door seal, and microwave generation and transmission systems shall be repaired, replaced, or b. Make the following safety checks on all ovens to be serviced adjusted by procedures described in service manual before before activating the magnetron or other microwave source, the oven is released to the owner. and make repairs as necessary: e. A microwave leakage check to verify compliance with the 1. Interlock Operation Federal Performance Standard should be performed on 2. Proper Door Closing each oven prior to release to the owner. 3. Seal and Sealing Surfaces (Arcing, Wear and Other Damage) 4. Damage to or Loosening of Hinges and Latches f. Do not attempt to operate the oven if the door glass is 5. Evidence of Dropping or Abuse broken.

c. Before turning on microwave power for any service test or inspection within the microwave generating compartments, check the magnetron, waveguide or transmission line, and cavity for proper alignment, integrity and connections.

W10844814A FOR SERVICE TECHNICIAN’S USE ONLY

FOR SERVICE TECHNICIAN’S USE ONLY

FAILURE CODE INDICATIONS

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, plug in microwave oven or reconnect power.

Display Likely Failure Recommended Repair Procedure Condition “Enter After a power failure, “Enter clock” will be flashing. Press CANCEL to end this indication. The colon (:) will clock” Power failure appear when in Standby mode. F1E4 Microwave ACU 1. Unplug microwave oven or disconnect power. 3. Replace all parts and panels before operating. F2E1 PCBA failure 2. Replace ACU PCBA. 4. Plug in microwave oven or reconnect power.

Stuck key failure 1. Unplug microwave oven or disconnect power. 3. Replace all parts and panels before operating. 2. Replace touch panel. 4. Plug in microwave oven or reconnect power.

F4E4 Humidity sensor 1. Enter the Diagnostics mode (press CANCEL – 6. Enter the Diagnostics mode (press CANCEL – error CANCEL- START), and then press COOK TIME CANCEL – START), then press COOK TIME, and

to display the humidity sensor reading. If display then press COOK POWER to see if failure code

does not show “3789,” continue to Step 2. Press reappears.

COOK POWER to display the RH sensor NTC NOTE: There may be a delay (approximately 1 reading. If display does not show “026,” continue minute, 20 seconds) before the F4E4 failure code to Step 2. is displayed.

2. Unplug microwave oven or disconnect power. 7. If the F4E4 failure code reappears, unplug

3. Connect a new humidity sensor PCBA to cable. microwave oven or disconnect power.

4. Replace all parts and panels before operating. 8. Replace ACU PCBA.

5. Plug in microwave oven or reconnect power. 9. Replace all parts and panels before operating.

10. Plug in microwave oven or reconnect power.

F8E5 Exhaust air 1. Enter the Diagnostics mode (press CANCEL – 5. Replace all parts and panels before operating. template CANCEL – START), and then press OPTIONS/ detection failure CLOCK to display the exhaust air temperature 6. Plug in microwave oven or reconnect power. sensor reading. Verify the sensor temperature 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/ If failure code matches complaint, continue to CLOCK to display the cavity temperature sensor Step 2. reading. Verify the sensor temperature reading. If it is still not correct, replace ACU PCBA. 2. Unplug microwave oven or disconnect power. 8. If failure does not reappear, stop. 3. Disconnect sensor from ACU PCBA.

4. Measure sensor resistance between connector pins and confirm reading is between 9.5kW and 10.5kW at room temperature. If measurement is not correct, or if a short or open circuit is found, replace sensor.

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PRIMARY, SECONDARY, AND MONITOR INTERLOCK SWITCH CHECKOUT PROCEDURES

IMPORTANT: Before checking the interlock switches, unplug microwave oven or disconnect power. Be sure to disconnect all of the wires at the switch being tested before making any continuity readings.

NOTE: The Secondary Interlock Switch is mounted in the door lock switch cradle independent of the Monitor Interlock Switch and Primary Interlock Switch. The Monitor Interlock Switch and the Primary Interlock Switch can be identified by the wire colors that are connected to the terminals of the switches. See the chart below for wire color designation.

Switch Check By Door Open Door Closed

Primary Interlock 1. Unplug microwave oven or disconnect power. – +

Monitor Interlock 2. Disconnect the wires at the Primary Interlock Switch. – Secondary Interlock 3. Check from the common terminal (black/brown wires) to the – normally open terminal (black/white wires). + 1. Unplug microwave oven or disconnect power. +

2. Disconnect the wires at the Primary Interlock Switch.

3. Check from the common terminal (black/brown wires) to the normally closed terminal (orange wire).

1. Unplug microwave oven or disconnect power. +

2. Disconnect the wires at the Monitor Interlock Switch.

3. Check from the common terminal (white wire) to the normally closed terminal (blue/white wires).

1. Unplug microwave oven or disconnect power. –

2. Disconnect the wires at the Secondary Interlock Switch.

3. Check from the common terminal (white/blue wires) to the normally open terminal (blue/blue wires).

(+) Continuity (-) No Continuity

NOTE: These diagrams are not intended to show a complete circuit; they represent the position of switches during “DOOR OPEN” or “DOOR CLOSED” (continuity checks only).

Door Closed Door Open

L (NC) (NO) N (NC) L (NC) (NO) N (NC)

(NO) (NC) P5-4 (NO) P5-2 (NO) (NC) P5-4 (NO) P5-2

Primary Monitor Secondary Primary Monitor Secondary Interlock Interlock Interlock Interlock Interlock Switch Switch Interlock Switch Switch Switch Switch

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NOT HEATING TROUBLESHOOTING INSTRUCTION

IMPORTANT: High voltage is present at the magnetron and high-voltage capacitor terminals. Avoid direct contact when power is connected to these components to avoid serious injury or possible death. Always be sure that the high-voltage capacitor is discharged before accessing any of these components.

For a no-heat condition, refer to the following step-by-step instructions:

1. Unplug microwave oven or disconnect power. Check for loose or failed connectors on the ACU PCBA (P1, P2, P4). If these check out OK, plug in microwave oven or reconnect 2. Discharge the high-voltage capacitor. power.

3. Disconnect the high-voltage transformer primary windings. Check for ACU PCBA failure. Refer to “ACU PCBA Pin Voltage Matrix.” 4. Attach the voltmeter leads to the high-voltage transformer primary input wires. 9. If the input voltage at the high voltage transformer primary input wires is close to the rating voltage 120 +/-15 VAC, unplug microwave 5. Plug in microwave oven or reconnect power. oven or disconnect power.

6. Close door and program the microwave oven to operate for 10. Check the power supply components. Refer to “Component Tests.” 30 seconds. High-voltage transformer 7. Press START. High-voltage capacitor 8. Check the input voltage at the high-voltage transformer primary input wires. If the voltage is not close to the rating voltage 120 High-voltage diode +/-15 VAC, unplug microwave oven or disconnect power. 11. If the power supply components check out OK, check the Check the circuitry as follows: connection between the magnetron and the high-voltage Measure resistance of the fuse, micro-switches, and transformer. thermostats. Replace any failed components. (Refer to the 12. If all of the components check out OK, replace the magnetron. wiring diagram.) 13. Reconnect the high-voltage transformer primary windings.

Check for loose terminals. (Refer to the wiring diagram.) Check all of the terminals on the main route from the power supply to the high voltage transformer.

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ACU PCBA PIN VOLTAGE MATRIX

Check for proper voltage by completing the following steps:

1. Unplug microwave oven or disconnect power. 3. Plug in microwave oven or reconnect power, and confirm voltage reading. 2. Connect voltage measurement equipment to the terminals listed below. (P1-3 and P2-1 are neutral.) 4. Unplug microwave oven or disconnect power.

NOTE: For 50V and over, the tolerance is +/-15V. For 0V, the tolerance is +/-3V.

Abbreviations

HL – Hood Light N –Neutral CL – Cavity Light HF – Hood Fan L – Line Voltage TT – Turntable Motor NFS – Neutral for Switch

NOTE: When checking voltage readings on ACU PCBA, connect the grounding test lead of voltmeter to P1-3, P2-1. Use the positive test lead to probe connectors designated below.

MW Oven Plugged In—Sitting Idle—ACV Readings MW Oven Running —ACV Readings

Pin Name Wire Color Power On, Hood Light— Hood Light— Door Closed High, Door Open Low, Door Open Power On, Hood Light—Low MW Oven Start Door Open Hood Fan Motor— High Hood Fan Motor— High, Door Open Hood Fan Motor— Med-High Hood Fan Motor— Med-High, Door Open Hood Fan Motor— Medium Hood Fan Motor— Medium, Door Open Hood Fan Motor— Low Hood Fan Motor— Low, Door Open Hood Light—High

P1-1 (L) Brown 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 P1-3 (N) White P2-3 (NFS) White 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P2-2 (Door) Orange P2-1 (N) Green 0 120 0 120 0 120 0 120 0 120 0 120 0 120 3.6 P4-4 (TT) Red P4-5 (CL) Green 0 120 0 120 0 120 0 120 0 120 0 120 0 120 49 P4-1 (HL) Yellow P4-2 (HF) Black 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P4-3 (HF-R) Gray 0 120 0 120 0 120 0 120 0 120 0 120 0 120 120

0 120 0 120 0 120 0 120 0 120 0 120 0 120 120

0 0 0 0 0 0 0 0 0 0 120 120 67 67 2.4

0 0 120 120 92 92 88 88 67 67 0 0 0 0 3.6

0 0 120 120 93 93 87 87 85 85 0 0 0 0 3.7

CONNECTORS ON ACU PCBA

P6 3 2 1 P3 14 13 12 11 10 9 8 7 6 5 4 3 2 1

Relay 2 P7

P9 1

4903 1 2 NOTE: There are purposely empty terminals between each of the numbered 1 2 P11 3 terminals on P1 connector.

PCBA 4

1 2 3 4 5

6

Relay 7

4903 8

P1 P4 2 P2 9

1.3 1 2 3 4 5 1 1 2 3 10

L N 11

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FOR SERVICE TECHNICIAN’S USE ONLY

TOUCH PANEL

Touch Panel and ACU PCBA Test

The microwave hood combination is provided with a self-diagnostic routine that can be accessed through the touch keypad.

To initiate this routine: All display segments will be lit to indicate the Test mode has been entered. 1. Plug in microwave oven or reconnect power, and press Cancel button to standby (“:”). NOTE: If the Cancel button is pressed during this diagnostic routine, you will exit the Test mode. 2. Close door, then press CANCEL – CANCEL – START within 3 seconds.

Key Tables for Test Mode

Key Name Function Display Buzzer Key Name Function Display Buzzer

Popcorn – key 30 1 beep 1 Cavity Light and Cooling CL 1 beep Potato or Baked – key 31 1 beep Fan On Potato 2 1 beep Vegetable – key 2E 1 beep Cavity Light, Cooling Fan CL TT Frozen Entree – key 33 1 beep 3 and Turntable On 1 beep Steam Simmer or – key 2D 1 beep 4 1 beep Steam Cook 5 – key 36 1 beep Warm Hold – 6 1 beep Reheat – – key 14 Defrost – 7 1 beep Soften/Melt – – key 15 Cook Time Humidity sensor check 8 1 beep key 06 1 beep Hood (Cooktop) Light On HL HIGH 1 beep 9 (High) 1 beep key 24 1 beep 0 1 beep 1 beep Hood (Cooktop) Light On HL LOW key 25 1 beep Light (Low) 1 beep Turntable 1 beep key 29 1 beep On/Off Vent Fan On (High HF HIGH Fan Speed) Value 1 beep Cancel between 1 beep Vent Fan On (Low Speed) HF LOW 2000 and 1 beep 6000 1 beep Microwave Oven MW

Value (1000W), CL, TT and CF between Cook Power RH NTC sensor check 10 On for 10 Seconds and 40 – key 03 key 07 – key 09 key 05 Cook – – key 04 1 beep Timer Set/Off HF NTC Thermistor XXX Exit Test Mode Options/Clock Software/Gee version : or xx.xx 1 beep Start check* xx.xx.xx – Add 30 Sec – key 20 1 beep Dinner Plate – key 32 1 beep Beverage – key 34 1 beep Pizza key 35 1 beep

*Continuously pressing the “START” key will respectively display SW Version and Gee Version for each press.

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FOR SERVICE TECHNICIAN’S USE ONLY

PARTS LAYOUT (NOT TO SCALE)

AB C

X D E FGH A. Line fuse (20 amp) M. Cooling fan motor W I B. AC line filter board N. HF NTC thermistor J C. Hood fan motor assembly O. ACU PCBA D. Cavity light P. Touch panel K E. Cavity light holder Q. Secondary interlock switch F. Magnetron R. Monitor interlock switch V L G. Magnetron thermostat— S. Primary interlock switch UT T. Turntable motor M opens at 257ºF (125ºC), U. Hood (cooktop) light N closes at 185ºF (85ºC) V. Hood (cooktop) light holder O H. Power resistor W. Cavity thermostat— I. H.V. capacitor J. H.V. diode opens at 257°F (125°C), K. H.V. transformer non-resettable L. Motor capacitor X. Humidity sensor PCBA

SR QP

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POWER OUTPUT MEASUREMENT

The power output of the magnetron can be measured using the following Output Test “Voltage Measurement” and “Output Test.” Before you perform the test:

Make sure that the oven cavity is cool and clean. 1. Fill the measuring cup with 2 cups (500 mL) of 70ºF (21ºC) tap water. Check the line voltage at the wall outlet while microwave oven is 2. Stir the water with the thermometer to ensure uniform temperature. operating. See “Voltage Measurement at Power Source.” Add warm or cool water to bring the water to the correct temperature. Tools Needed 3. Place the measuring cup in the center of the microwave oven cavity. 2-cup measuring cup Thermometer 4. Operate the microwave oven on High speed for 1 minute. Voltmeter/ohmmeter 5. Remove the measuring cup and stir the water with the thermometer Voltage Measurement at Power Source for about 20 seconds.

1. Fill the measuring cup with 2 cups (500 mL) of tap water. 6. Record the temperature of the water. 2. Place in the center of the microwave oven cavity. 3. Operate the microwave oven on High speed for 1 minute. 7. Refer to the model serial tag on the microwave oven to acquire 4. While the microwave oven is operating, measure the line voltage wattage output rating of the microwave oven.

at the power source. See “Measure Voltage” illustration. 8. Using the following chart, determine if the output of the microwave 5. Verify the voltage is constant during microwave oven operation. If oven is within the range listed based on the line voltage and wattage rating of the microwave oven. voltage drops below 108V, contact a qualified electrician to check your electrical supply. Water Temperature for Line Voltage and Wattage Rating 6. Make note of the voltage while the microwave oven is running and proceed to the output test. Voltage 700W 1000W 1200W

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 (33ºC to 36ºC) (38ºC to 42ºC) (44ºC to 47ºC)

Measure Voltage

A B

C

A. House power supply wall outlet B. Voltmeter/ohmmeter test leads C. Microwave oven plug

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FOR SERVICE TECHNICIAN’S USE ONLY

COMPONENT TESTS

IMPORTANT:

Unplug microwave oven or disconnect power. Conduct a microwave energy test after performing any tests or repairs to the microwave oven. Discharge the high-voltage capacitor and remove the lead wires from the primary winding of the high-voltage Check that all wire leads are in the correct positions before transformer before conducting any of the following tests. operating the microwave oven.

Remove the lead wires from the related component before Grasp wire connectors when removing the wire leads from conducting any of the following tests. microwave oven parts.

All operational checks using microwave energy must be All testing must be done with an ohmmeter having a done with the microwave oven loaded with a minimum of sensitivity of 20,000 ohms per volt DC or greater, and 8 oz (250 mL) of water in a microwave-safe container. powered by at least a 9-volt battery.

Components Test/Results

H.V. Transformer 1. Unplug microwave oven or disconnect power. Filament 2. Remove wire leads. (orange/red wires) 3. Measure resistance: Primary Secondary (white Primary winding: Less than 0.5 ohm (approximate) wire – ground to Secondary winding: 120 ohms (approximate) transformer case) Filament winding: 0 ohms Primary winding to grounding: Normal: Infinite Magnetron Filament winding to grounding: Normal: Infinite 1. Unplug microwave oven or disconnect power. H.V. Capacitor 2. Remove wire leads. 3. Measure resistance: H.V. Diode Filament terminal: Normal: Less than 1 ohm Filament to chassis: Normal: Infinite Turntable Motor 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance: Terminal to terminal: Normal: Momentarily indicates several ohms and then gradually returns to infinite. Terminal to case: Normal: Infinite

NOTE: Some inexpensive meters may indicate infinite resistance in both directions. 1. Unplug microwave oven or disconnect power. 2. Measure resistance:

Forward: Normal: Continuity Reverse: Normal: Infinite 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance: Normal: 2.4k to 3.2k ohms (approximate)

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FOR SERVICE TECHNICIAN’S USE ONLY

ComponentsP5 Test/Results 3551 Motor Capacitor 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. Humidity Sensor PCBA 3. Measure resistance:

1 Normal: Momentarily 0 ohms, then goes to infinite 2 3 1. Unplug microwave oven or disconnect power. 4 2. Remove the 4-pin connector from the cable. 3. Measure resistance across pins 1 and 2. Hood Exhaust Fan Motor Normal: 10k ohms +/-5% at 77°F (25°C) HF NTC Thermistor 4. Measure capacity value across pins 3 and 4.

Power Resistor Normal: 180pF +/-5% at 55% RH

Cooling Fan Motor 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance:

High Speed—Normal: Red (RD) and Blue (BU) wires: 70 to 100 ohms (approximate); Blue (BU) and Black (BK) wires: 30 to 60 ohms (approximate)

Low Speed—Normal: Red (RD) and Blue (BU) wires: 70 to 100 ohms (approximate); Blue (BU) and White (WH) wires: 50 to 80 ohms (approximate)

1. If “NTC SHORT, CALL FOR SERVICE” or “NTC OPEN, CALL FOR SERVICE” scrolls on display, unplug microwave oven or disconnect power.

2. Measure resistance:

Normal: 10k ohms +/-5% at 77ºF (25ºC)

1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance:

Normal: 20 ohms/25W

1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance:

Normal: 40 to 60 ohms (approximate)

AC Line Filter Board 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure resistance:

Normal: L-IN to L-OUT (coil): Less than 1 ohm; N-IN to N-OUT (coil): Less than 1 ohm

Thermostats NOTE: Refer to “Parts Layout” for opening and closing temperatures. 1. Unplug microwave oven or disconnect power. Cavity Thermostat 2. Remove wire leads. Magnetron Thermostat 3. Measure continuity:

Normal: Continuity

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Cavity Secondary Magnetron Thermostat Interlock Thermostat

4 BU WH Switch BU WH FOR SERVICE TECHNICIAN’S USE ONLY2 High-Voltage L Components SCHEMATIC DIAGRAM WH BU Motor BU BU P5-2WH Red Tube Magnetron Black TubeCapacitorBlack Tube AC 120V/125V 60Hz P5-4 YL YL RD RD BUTT CF FA 11 POWER CORD F LN Cy WhiteWH P6-3 P6-5 Monitor P5-1 RD Cx Tab BU White Interlock Cy HL Tab Switch RD G WH Golden HF CL Tab WH YL/GN Golden BK BK P5-5 Tab H.V. RD Power WH Capacitor Resistor BK H.V. GY Diode Fuse P6-2 Primary H.V. Interlock Transformer 20AMP L WH Switch BK

P6-1

BK

1 AC Line Filter 3 P1-3 WH P2-3 WH P4-4 RD P4-1 YL P1-1 BR P4-5 GR OR P2-1 GR BR P4-3 GY BK P2-2 P4-2 BK

N HL L R HF CL DOOR N NFS TTM 68K 33K

33K 2 1 P6 HUM YL/GN TRIAC HF relay SMPS 4903 Sensor 7919 4912 DWG NO.: MU-148-T CL Relay TT Relay Fuse PCBA P9 CONDITION: DOOR OPEN TRIAC 4901 4902 HF SYMBOL NOTES: 7915 NTC

BK: WIRE COLOR HL Hood (Cooktop) BK CL Cavity BK: Black OR: Orange ACU PCBA: Appliance Control Unit Printed Circuit Board Assembly Light Light BU: Blue YL: Yellow P1/P2/P4/P5/P6/P9/P12: Connectors WH HF Hood Fan RD: Red GN: Green P6-1 PIN NO.–1 BU Motor WH: White GY: Gray BR: Brown YL/GN: Yellow/Green CONNECTOR FCM Forced YL TT Turntable NAME Convection Motor Motor RD

FOR SERVICE TECHNICIAN’S USE ONLY

W10844814A 12/15

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