TechSheet-W10619042-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: Verify the controls are in the off position so that the appliance does not start when energized. Allow enough space to perform the voltage measurements without obstructions. Keep other people a safe distance away from the appliance to prevent potential injury. Always use the proper testing equipment. 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.

W10619042A 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 the Diagnostics Mode (press CANCEL – CANCEL – START) and press COOK TIME/POWER to verify the failure code. If the failure code displayed matches complaint, see chart below for details.

F1E4 Microwave ACU 1. Unplug microwave oven or disconnect power. 3. Replace all parts and panels before operating.

PCBA failure 2. Replace ACU PCBA. 4. Plug in microwave oven or reconnect power.

F2E1 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 to CANCEL – START), and then press COOK to

display the humidity sensor reading. If display see 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 failure code

3. Connect a new humidity sensor to the ACU is displayed.

PCBA P6 connector. 7. If the failure code reappears, unplug

4. Replace all parts and panels before operating. microwave oven or disconnect power.

5. Plug in microwave oven or reconnect power. 8. Replace ACU PCBA.

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. temperature detection failure CANCEL – START) and then press WARM 6. Plug in microwave oven or reconnect power. from Hood NTC HOLD to display the Hood NTC thermistor reading. Verify the temperature reading is at 7. Enter the Diagnostics Mode (press (CANCEL – CANCEL – START), and then press WARM room temperature (typically 50ºF to 90ºF [10ºC HOLD to display the Hood NTC thermistor to 32ºC]) and verify failure code. If failure code reading. Verify the temperature reading. If it is matches complaint, continue to Step 2. still not correct, replace ACU PCBA. 2. Unplug microwave oven or disconnect power. 8. If failure does not reappear, stop. 3. Disconnect Hood NTC thermistor cable from

ACU PCBA P9 connector.

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

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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 taking any ohm 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.

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).

Monitor Interlock 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).

Secondary Interlock 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 Switch Switch Interlock Switch Switch Interlock

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 2. Use a 20,000 ohm, 2 watt resistor to discharge the high oven or reconnect power. voltage capacitor. Check for ACU PCBA failure. Refer to “ACU PCBA Pin 3. Disconnect the high voltage transformer primary windings. Voltage Matrix.”

4. Attach the voltmeter leads to the high voltage transformer 9. If the input voltage at the high voltage transformer primary primary input wires. input wires is close to the rating voltage 120 +/- 15 VAC, unplug microwave oven or disconnect power. 5. Plug in microwave oven or reconnect power. 10. Check the power supply components. Refer to “Component 6. Close door and program the microwave oven to operate for 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 High voltage diode voltage 120 +/- 15 VAC, unplug microwave oven or disconnect power. Check the circuitry as follows: 11. If the power supply components check out OK, check the connection between the magnetron and the high voltage Measure resistance of the fuse, microswitches and transformer. thermostats. Replace any failed components (refer to the wiring diagram). 12. If all of the components check out OK, replace the magnetron. Check for loose terminals (refer to the wiring diagram). Check all of the terminals on the main route from the 13. Reconnect the high voltage transformer primary windings. 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. (P1-2, P2-3 and P2-4 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 NFS– Neutral for

HL– Hood Light N–Neutral CF– Cooling Motor HF– Hood Fan L– Line Voltage TT– Turntable Motor Switch

NOTE: When checking voltage readings on ACU PCBA, connect the grounding test lead of voltmeter to ACU PCBA neutral wire. Use the positive test lead to probe connectors designated below.

Table of MW Oven Plugged In—Sitting Idle—Volt AC Readings MW Oven Running —VAC Readings

Pin Name Wire Color Power On, Power On, Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Fan Motor— Hood Light— Hood Light— Hood Light— MW Oven Start Door Closed Door Open (1) (1), Door Open (2) (2), Door Open (3) (3), Door Open (4) (4), Door Open (5) (5), Door Open (6) (6), Door Open High High, Door Open Low Hood Light— Low, Door Open

P1-1 (L) Brown 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120 120

P1-2 (N) White 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6

P2-1 (NFS) White 0 120 0 120 0 120 0 120 0 120 120 120 120 120 0 120 0 120 6.3

P2-2 (Door) Orange 0 120 0 120 0 120 0 120 0 120 120 120 120 120 0 120 0 120 50

P2-3 (N) Green 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6

P2-4 (N) Blue 000 0 0 0 0 0 00 0 0 0 0 0 000 6

P4-2 (TT) Red 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 120

P4-3 (CL) Green 0 120 0 120 0 120 0 120 0 120 120 120 120 120 0 120 0 120 120

P4-4 (HL) Yellow 0 0 0 0 0 0 0 0 0 0 0 0 0 0 120 120 68 68 0

P4-5 (HF) Black 0 0 120 120 84 84 75 75 63 63 57 57 52 52 0 0 0 0 0

P4-6 (HF-R) Gray 0 0 120 120 84 84 80 80 70 70 60 60 70 70 0 0 0 0 0

CONNECTORS ON ACU PCBA

P1 P4 P2 N 2.1 L 6. 5. 4. 3. 2. 1 4.3.2.1

NOTE: There are purposely empty terminals between each of the numbered terminals on P1, P2 and P4 connectors.

P6

ACU PCBA P9

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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: 3. Open door. The model number will be displayed. 1. Plug in microwave oven or reconnect power and press 4. Close door. All display segments will be lit. CANCEL button to standby (“:”). NOTE: If the CANCEL button is pressed during this diagnostic 2. Close door, then press CANCEL – CANCEL – START within routine, you will exit the test mode. 3 seconds.

All display segments will be lit to indicate the test mode has been entered. In the upper left corner of the display, the condition of the ACU PCBA will be displayed (“GOOD”), or the most recent error code.

Key Tables for Test Mode

Key Name Function Display Buzzer Key Name Function Display Buzzer Select Choice Start/Add 1 min Display UI SW, UI:00.12.04, Yes Frozen Entree – key 27 1 beep Timer Set/Off ACU PCB SW, ACU:03.00.00, Options/Clock – key 15 1 beep

Touch SW and TH:00.03.00 and 1 2 EE PROM data EE:00.07.00 3 Erase Service Error GOOD 1 beep Records Version (alternating) 4 5 Hood Light – key 30 1 beep 6 Error history check If no error 1 beep 7 history: GOOD Vent Fan – key 28 1beep 8 If error history: Reheat – key 08 1 beep 9 FxEx FxEx..

Popcorn – key 13 1 beep 0 Cavity Light On Cavity Light 1 beep

Defrost – key 05 1 beep Cancel Cavity Light and Light and 1 beep Turntable On Turntable Potato – key 14 1 beep

Soften/Melt – key 09 1 beep TT, CL, MW Relay MW Turbo On 1 beep 4913 & 4903 Vegetable – key 06 1 beep (1000W) On for 10 seconds Warm Hold Hood NTC 0000-0120 1 beep ambient temperature – key 34 1 beep check – key 35 1 beep

Cook Humidity 7000-9999 1 beep Hood Light Hood Light High 1 beep Relay 4910 On Sensor Check

Cook Failure history If no error history: 1 beep Hood Light Relay Hood Light Low 1 beep Time/Power check GOOD 4909 On

If error history: Vent Fan Relay Hood Fan HIGH 1 beep FxEx YY FxEx YY… 4911 On (High Speed) Kids Menu – key 10 1 beep

– key 45 1 beep Vent Fan On Relay Hood Fan LOW 1 beep 4911 Off > (Low Speed)

Turntable – key 29 1 beep TT, CL, MW Relay MW 1 beep key 46 1 beep 4903 (900W) On for >- 10 Seconds

Exit Test Mode Timer 1 beep

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PARTS LAYOUT (NOT TO SCALE)

AB C

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

opens at 257°F (125°C), non-resettable AB. Humidity sensor

TS R

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FOR SERVICE TECHNICIAN’S USE ONLY

POWER OUTPUT MEASUREMENT

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

Tools Needed 3. Place the measuring cup in the center of the microwave oven cavity.

2-cup measuring cup 4. Operate the microwave oven on high power for 1 minute. Thermometer Voltmeter/ohmmeter 5. Remove the measuring cup and stir the water with the thermometer for about 20 seconds.

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 wattage output rating of the microwave oven.

1. Fill the measuring cup with 2 cups (500 mL) of tap water. 8. Using the following chart, determine if the output of the 2. Place in the center of the microwave oven cavity. microwave oven is within the range listed based on the line voltage and wattage rating of the microwave oven.

3. Operate the microwave oven on high power for 1 minute. Water Temperature for Line Voltage and Wattage Rating

4. While the microwave oven is operating, measure the line Voltage 700W 1000W 1200W voltage at the power source. See “Measure Voltage” illustration. 120V 96ºF to 102ºF 110ºF to 116ºF 124ºF to 130ºF (36ºC to 39ºC) (43ºC to 47ºC) (51ºC to 54ºC) 5. Verify the voltage is constant during microwave oven operation. If voltage drops below 108V, contact a qualified 108V 91ºF to 97ºF 101ºF to 107ºF 111ºF to 117ºF electrician to check your electrical supply. (33ºC to 36ºC) (38ºC to 42ºC) (44ºC to 47ºC)

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 Primary winding: Less than 0.5 ohm (approximate) Secondary (white Secondary winding: 120 ohms (approximate) wire – ground to Filament winding: 0 ohms transformer case) Primary winding to grounding: Normal: Infinite Filament winding to grounding: Normal: Infinite Magnetron 1. Unplug microwave oven or disconnect power. H.V. Capacitor 2. Remove wire leads. 3. Measure resistance: Motor Capacitor Filament terminal: Normal: Less than 1 ohm Cooling Fan Motor Filament to chassis: Normal: Infinite

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

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

Normal: Momentarily 0 ohms, then goes to infinite

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

Normal: 40 to 60 ohms (approximate)

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Components Test/Results

H.V. Diode 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

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

Normal: 2.8k ohms (approximate)

Humidity Sensor 1. Unplug microwave oven or disconnect power. 2. Remove the 3-pin connector from the electronic control (P6). W R NOTE: Do not remove the attached resistor, which is used for internal resistance calibration. BK 3. Measure resistance across pins 1 and 3, and across pins 2 and 3: Resistor Normal: 2.8k ohms (approximate) at 77ºF (28ºC) +/- 18ºF (-10ºC)

Hood Fan Motor 1. Unplug microwave oven or disconnect power.

2. Remove wire leads.

3. Measure resistance:

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

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

Hood Fan Thermistor 1. If “NTC SHORT, CALL FOR SERVICE” or “NTC OPEN, CALL FOR SERVICE” scrolls on display, unplug microwave oven or disconnect power. P5 3551 2. Measure resistance:

Normal: 10k ohms +/- 5% at 77ºF (25ºC)

Power Resistor250V FUSE20A 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. AC Line Filter Board 3. Measure resistance:

L-IN N-IN N-OUT Normal: 20 ohms/25W 1. Unplug microwave oven or disconnect power. L-OUT 2. Remove wire leads. 3. Measure resistance: Thermostats Normal: L-IN to L-OUT (coil): Less than 1 ohm; N-IN to N-OUT (coil): Less than 1 ohm Magnetron/ Cavity Thermostat NOTE: Refer to “Parts Layout” for opening and closing temperatures. 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 3. Measure continuity:

Normal: Continuity

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AC Line Filter Board Secondary Magnetron Interlock Switch Thermostat

2 N-In N-Out 4 BU W BU W L W Cavity FOR SERVICE TECHNICIAN’S USE ONLY Thermostat BU Motor BU SCHEMATIC DIAGRAMMagnetron Capacitor Red Tube Cy BU W Black Tube Black TubeFA P5-4 HF RR P5-2 N W YY BU BU BU CF White W P6-3 P6-5 White Tab Tab G R Interlock R Cx Switch Monitor TT W

Y/G HL HL HF CL BK

L Cy BK Golden W Tab AC 120V / 125V 60 Hz H.V. R Capacitor

R Golden Tab Main P6-2 P6-1 BK Fuse P5-5 W 20 Power Cord BK Amp L BK P4-5 Primary P5-1 Turbo Fuse 20 Amp BK Power 1 L-In GY Resistor GY Interlock H.V. Diode BK P4-6 Switch H.V. L-Out 3 BR P1-1 Transformer

Y P4-4 W P2-1 R P4-2 BK G P2-3 W P1-2 BU P2-4 R

OR P2-2 G P4-3

N HL L R HF CL Door N N NFS TT P6 HS Diode 6908 Humidity HF Relay 4911 33K MW Relay No Nc Sensor HL Relay 4909 4903 2 1 P9 Y/G HL Relay 4910 Hood NTC Thermistor Dwg. No.: MU-133-T CL Relay TT Relay SMPS MW Turbo Condition: Door Open. 4901 Fuse Relay 4913 Symbol Notes: 4902

BK Wire Color – Black Triac P6-1 Pin No. -1 7915

Connector Name ACU PCBA

HL Hood (Cooktop) BK CL Cavity BK: Black OR: Orange Light W Light BU: Blue Y: Yellow BU HF Hood Fan G: Green Motor R: Red ACU PCBA: Appliance Control Unit Printed Circuit Board Assembly CL Cooling Y TT Turntable W: White GY: Gray P1/P2/P/P4/P5/P6/P9: Connectors Fan Motor R Motor BR: Brown Y/G: Yellow/Green

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W10619042A 11/13 FOR SERVICE TECHNICIAN’S USE ONLY © 2013. All rights reserved.