TechSheet-W11038367-RevB
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, and the oven is released to the owner. make repairs as necessary: e. A microwave leakage check to verify compliance with the 1. Interlock Operation Federal Performance Standard should be performed on each oven prior to release to the owner. 2. Proper Door Closing f. Do not attempt to operate the oven if the door glass is 3. Seal and Sealing Surfaces (Arcing, Wear and Other Damage) broken.

4. Damage to or Loosening of Hinges and Latches

5. Evidence of Dropping or Abuse

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.

W11038367B 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 F2E1 PCBA failure 1. Unplug microwave oven or disconnect power. 3. Replace all parts and panels before operating. F4E4 Stuck key failure 2. Replace ACU PCBA. 4. Plug in microwave oven or reconnect power.

F8E5 Humidity sensor 1. Unplug microwave oven or disconnect power. 4. Plug in microwave oven or reconnect power. error 2. Replace keypad. 3. Replace all parts and panels before operating. 5. If problem persists, refer to “PCBA Pin Voltage Exhaust air template Matrix.” detection failure 1. Enter the Diagnostics mode (press CANCEL – 6. Enter the Diagnostics mode (press CANCEL – CANCEL – START), and then press COOK to CANCEL – START), and then press COOK to see display the humidity sensor reading. If display if failure code reappears. does not show “8891,” continue to Step 2. NOTE: There may be a delay (approximately 2. Unplug microwave oven or disconnect power. 1 minute, 20 seconds) before the F4E4 failure code is displayed. 3. Connect a new humidity sensor to the ACU PCBA P6 connector. 7. If the F4E4 failure code reappears, unplug 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.

1. Enter the Diagnostics mode (press CANCEL – 5. Replace all parts and panels before operating. CANCEL – START), and then press OPTIONS/ 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. – + 2. Disconnect the wires at the Primary Interlock Switch. Monitor Interlock 3. Check from the common terminal (black/brown wires) to the + – Secondary Interlock 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 2. Discharge the high-voltage capacitor. or reconnect 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 the “Component 30 seconds. Tests” section.

7. Press START. High-voltage transformer

8. Check the input voltage at the high-voltage transformer primary High-voltage capacitor input wires. If the voltage is not close to the rating voltage 120+/-15 VAC, unplug microwave oven or disconnect power. Check the circuitry as follows:

Measure resistance of the fuse, micro-switches and High-voltage diode thermostats. Replace any failed components (refer to the wiring diagram). 11. If the power supply components check out OK, check the connection between the magnetron and the high-voltage Check for loose terminals (refer to the wiring diagram). Check all transformer. of the terminals on the main route from the power supply to the high voltage transformer. 12. If all of the components check out OK, replace the magnetron.

13. Reconnect the high-voltage transformer primary windings.

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

HL – Hood Light N – Neutral

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 probe connectors designated below.

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

Pin Name Wire Color Power On, Power On, Hood Fan Motor— Hood Light— Hood Light— Door Closed Door Open High High, Door Open Low, Door Open Hood Fan Motor— Hood Light—Low MW Oven Start High, Door Open Hood Fan Motor— Med-High Hood Fan Motor— Med-High, 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 P1-3 (N) White P2-3 (NFS) White 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 3.6 P4-4 (TT) White P4-5 (CL) Red 0 120 0 120 0 120 0 120 0 120 0 120 49 P4-1 (HL) Yellow P4-2 (HF-R) Gray 0 0 0 0 0 0 0 0 0 0 0 0 0 P4-3 (HF-Hi) Black P4-6 (HF-Lo) Blue 0 120 0 120 0 120 0 120 0 120 0 120 120

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

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

0 0 120 120 120 120 77 77 0 0 0 0 3.6

0 0 120 120 68 68 39 39 0 0 0 0 3.7

0 0 151 151 120 120 77 77 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

P9 Relay 2 P7 4903 1 1 2 NOTE: There are purposely empty 3 terminals between each of the numbered 1 2 P11 4 terminals on P1 connector.

PCBA 1 2 3 4 5

6 Relay 7 4903 8 9 P1 P4 2 P2 10 11 1.3 123456 1 1 2 3

L N

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TOUCH PANEL

Touch Panel and ACU PCBA Test

To initiate diagnostic routine: 3. Open door. The model number will be displayed.

1. Plug in microwave oven or reconnect power and press CANCEL to 4. Close door. All display segments will be lit. Standby (“:”). 5. Press indicated keypad for correct display readout and beep. 2. Close door, then press CANCEL – CANCEL – START within 3 seconds. NOTE: If Cancel is pressed during this diagnostic routine, you will exit the Test mode. All display segments will be lit to indicate the Test mode has been entered.

Key Tables for Test Mode

Key Name Function Display Buzzer Key Name Function Display Buzzer

Popcorn – key 30 1 beep 3 – key 36 1 beep Baked Potato – key 31 1 beep 4 1 beep Reheat – key 24 1 beep 5 – key 14 1 beep Defrost – key 25 1 beep 6 1 beep Soften/Melt – key 29 1 beep – key 15 Cook Time – key 21 1 beep 7 1 beep Cook Power – key 22 1 beep Hood (Cooktop) HL HIGH Auto Cook Humidity sensor check XXX 1 beep 8 Light On (High) 1 beep Kitchen Timer – key 05 1 beep On/Off 9 Hood (Cooktop) HL LOW 1 beep Clock/Options 0 Light On (Low) 1 beep Start Add 30 Sec Pizza Light Vent Fan On HF HIGH 1 beep 1 Off/High/Low (High Speed) Turntable 2 3 Speed Fan Vent Fan On (Low Speed) HF LOW Off/On Cancel Microwave Oven MW

(1000W), CL, TT,

HF NTC Thermistor XXX 1 beep and CF On 03.00.00* 1 beep Software version check key 35 1 beep – key 03 CL 1 beep – – key 09 1 beep CL TT 1 beep Cavity Light and Cooling – key 04 1 beep Fan On Exit Test Mode : or xx.xx 1 beep Cavity Light, Cooling Fan and Turntable On

* May be higher, depending on software upgrades at time of production.

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PARTS LAYOUT (NOT TO SCALE)

AB C

X DE A. Main fuse (20 amp) M. HF NTC thermistor W FG B. AC line filter board N. ACU PCBA H C. Hood fan motor assembly O. Touch panel V I D. Cavity light P. Secondary interlock switch E. Cavity light holder Q. Monitor interlock switch J F. Magnetron R. Primary interlock switch G. Magnetron thermostat— S. Turntable motor K T. Hood (cooktop) light opens at 257ºF (125ºC), U. Hood (cooktop) light holder U closes at 185ºF (85ºC) V. Motor capacitor H. Power resistor W. Cavity thermostat— T I. H.V. capacitor S J. H.V. diode opens at 329°F (165°C), K. H.V. transformer non-resettable L. Cooling fan motor X. Humidity sensor

R L Q M

N

PO

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POWER OUTPUT MEASUREMENT

The power output of the magnetron can be measured using the following Output Test “Voltage Measurement at Power Source” and “Output Test” sections. Before you perform the test: 1. Fill the measuring cup with 2 cups (500 mL) of 70ºF (21ºC) tap water. 2. Stir the water with the thermometer to ensure uniform temperature. Make sure that the oven cavity is cool and clean. Add warm or cool water to bring the water to the correct Check the line voltage at the wall outlet while microwave oven is temperature. operating. See the “Voltage Measurement at Power Source” section.

Tools Needed 3. Place the measuring cup in the center of the microwave oven cavity. 4. Operate the microwave oven on high power for 1 minute.

2-cup measuring cup 5. Remove the measuring cup and stir the water with the thermometer Thermometer for about 20 seconds. Voltmeter/ohmmeter 6. Record the temperature of the water. Voltage Measurement at Power Source 7. Refer to the model serial tag on the microwave oven to acquire 1. Fill the measuring cup with 2 cups (500 mL) of tap water. wattage output rating of the microwave oven.

8. Using the following chart, determine if the output of the microwave oven is within the range listed based on the line voltage and wattage rating of the microwave oven.

2. Place in the center of the microwave oven cavity. Water Temperature for Line Voltage and Wattage Rating

3. Operate the microwave oven on high power for 1 minute. Voltage 700W 1000W 1200W

4. While the microwave oven is operating, measure the line voltage at 120V 96ºF to 102ºF 110ºF to 116ºF 124ºF to 130ºF the power source. See “Measure Voltage” illustration. (36ºC to 39ºC) (43ºC to 47ºC) (51ºC to 54ºC)

5. Verify the voltage is constant during microwave oven operation. If 108V 91ºF to 97ºF 101ºF to 107ºF 111ºF to 117ºF voltage drops below 108V, contact a qualified electrician to check (33ºC to 36ºC) (38ºC to 42ºC) (44ºC to 47ºC) your electrical supply.

6. Make note of the voltage while the microwave oven is running, and proceed to the output test.

Measure Voltage

A B

C

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

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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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ComponentsP5 Test/Results 3551 Motor Capacitor 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. Humidity Sensor 3. Measure resistance: WH RD Normal: Momentarily 0 ohms, then goes to Infinite. BK 1. Unplug microwave oven or disconnect power. Resistor 2. Remove the 3-pin connector from the electronic control (P6). Hood Exhaust Fan Motor NOTE: Do not remove the attached resistor which is used for internal resistance calibration. HF NTC Thermistor 3. Measure resistance across pins 1 and 3, and across pins 2 and 3:

Power Resistor Normal: 2.8k ohms (approximate) at 77ºF (28ºC)+/-18ºF (-10ºC)

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: 65 ohms/65W

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 the “Parts Layout” section 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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FOR SERVICE TECHNICIAN’S USE ONLYCavitySecondary Magnetron High Voltage Thermostat Interlock Thermostat Components SCHEMATIC DIAGRAMSwitch 2 4 BU WH BU WH Black TubeLP5-3 BU P6-3 BU 11 WH BU YL YL BU Motor BU TT CF Red Tube Magnetron RD RD Capacitor Black Tube AC 120V/125V 60Hz P5-4 BU BUP5-1 FA POWER CORD P6-5 WH F White LN Cy YL Tab Monitor RD Cx Interlock HL Switch RD Cy Y/G Golden HF White WH WH YL/GN Tab Tab BK H.V. BK RD P5-5 Cement R CL Capacitor

BK GNP6-2WH Golden Tab BK Fuse Primary H.V. P6-1 Interlock 20AMP L BK Switch H.V. Diode

1 3 P1-1 BR Transformer P4-2 GY AC Line Filter P1-3 WH P4-1 YL P4-3 BK P4-6 BU P4-4 WH OR

P2-2 P2-1 GN P2-3 WH P4-5 RD

BK RD

DWG NO.: MU-147-T (Rev. B) N HL L R HF HF relay CL Door N NFS TTM P6 HUM HF relay 4911 33K Sensor 4912 2 No Nc P9 HF NTC 1

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

HF relay Fuse 68K 33K 4917 PCBA CONDITION: DOOR OPEN

SYMBOL NOTES:

BK WIRE COLOR P2/P3/P4/P5/P6/P7: CONNECTORS BK BLACK WH: WHITE BR: BROWN P6-1 PIN NO. –1 HL HOOD LAMP C F COOLING FAN MOTOR BK HOOD FAN MOTOR BU BLUE GN: GREEN OR: ORANGE CONNECTOR (COOKTOP LAMP) TT TURNTABLE MOTOR RD: RED YL: YELLOW GY: GRAY NAME WH HF

BU YL RD

CL CAVITY LAMP

FOR SERVICE TECHNICIAN’S USE ONLY

For patent information, please see Pat. www.patent-listing.com W11038367B NOTE: This sheet contains important Technical Service Data. W11038367B FOR SERVICE TECHNICIAN ONLY ©2016. All rights reserved. DO NOT REMOVE OR DESTROY

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