tech-sheet-8205280
Tech Sheet Do not discard

WARNING

Electrical Shock Hazard Disconnect power before servicing. Replace all parts and panels before operating. Failure to do so can result in death or electrical shock.

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 d. Any defective or misadjusted components in the the door open. interlock, monitor, door seal, and microwave generation and transmission systems shall be repaired, b. Make the following safety checks on all ovens to be replaced, or adjusted by procedures described in serviced before activating the magnetron or other service manual before the oven is released to the microwave source, and make repairs as necessary: owner.

1. Interlock Operation e. A microwave leakage check to verify compliance with the Federal Performance Standard should be 2. Proper Door Closing performed on each oven prior to release to the owner.

3. Seal and Sealing Surfaces (Arcing, Wear and Other f. Do not attempt to operate the oven if the door glass is 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.

8205280 / 4619-651-98881 FOR SERVICE TECHNICIAN’S USE ONLY

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120V/125V, 60Hz Primary Interlock 23 OR

L BK AC Line Filter L1 1 BR Fuse 2 BR Switch 4 BR 6 R P32 P33 5 W 2P84 1Cy20 Amp 2P81 52 W TR CN701 32 W TR GND Cx R Coil Cx 28 BU Base 1P91 55 W 5P81 31 W Y HL HL VDR Thermostat TT 50 W 1P81 51 W Y G Cy Monitor Interlock 6P81 2P83 Grill W Magnetron 49 BU 2P91 4P81 CF Thermostat 1P84 N P31 ThermistorN1 Switch 3P81 1 1P83 11 BU P58 P35 P34 Relay 4924 Quartz Grill Heater P86 1 VDR VDR R1 Door 15 BU WIRING DIAGRAMS CL R P63 NFS Halogen Grill Element P88 P62 13 W 27 BU W / 3C P54 1 10 W 12 BKP53 1 Schematic Diagram P57 Relay Control Board P67 Softstart Quartz Tube P89TT CF FCFA Relay Board 45 Y/G 3 Cavity 14 BK P85 47 R1 Thermostat GY/5C 46 RCN701 42 BU 29 BU P2 P66 BK / R / 10 C P56 39 BU 36 R UIB Thermistor UIB P64 10 HF Triac 35 BR MW Relay 7190 33 BK LCD P3 feedback BK 1 CF Relay 2 2 2 2 Inverter BK 1 56 W TT Relay 4901 1 MW 1 Inverter 53 BK 4906 Relay CN702 4903 Waveguide 3 BR 17 BK 2 P90 Thermostat 34 BU CN703 54 BU E701 1 P74 Y / 3C P61 3 Fuse Fuse 1 1 1

500mA Inverter 500mA L N Softstart Grill Heater P55 4121 4170 Relay Relay Relay 1

P65 4924 4914 4904 P51 P52 20 BU

P68 P73 21 BK 22 GY 1 1 57 W 7P81 37 R 58 R 8P81 55Y/G 3P82 R 38 R 24 G 2P82 W 1P82 BK P62-2/NFS

R/W Secondary W Interlock Switch 19 W BK R W P21 10uF/400V Humidity Hood/Light 18 BU Magnetron Sensor Switch Motor Capacitor HF Hood Exhaust 26 BU Fan Motor

Condition: Door Open. P21/P31/P32/P33/P34/P35/P51/P52/P53/P54/P55/P56/P57 DWG NO. MU-084 Symbol Notes /P58/P61/P62/P63/P64/P65/P66/P67/P68/P71/P72/P73/ P74/CN701/CN702/CN703: Wire to PCB Connectors 1BR CF Cooling Fan Motor Wire Color – Brown CL Cavity Lamp P81/P82/P83/P84: Wire to Wire Connectors Wire No. – 1 P85/P86/P88/P89/P90: Wire to Relay Connectors Hood Lamp BK 45 W / 3C Ribbon Cable / 3 Core HL (Cooktop Lamp) W HF Hood Exhaust BK: Black W: White BR: Brown OR: Orange TT Turntable Motor R Fan Motor BU: Blue G: Green GY: Gray

R: Red Y: Yellow

TR: Transparent

Parts Layout

(not to scale)

CC BB A AA B

CD

E F

G H I

J

K

X L

DD EE Z Y UX W M

V U TS N R Q PO

A. Halogen grill element L. Inverter W. Turntable motor B. Softstart quartz tube M. Cooling fan motor X. Touch panel board (back and front C. Quartz grill heater N. Motor capacitor D. Grill thermostat—opens at 293ºF O. Monitor interlock switch views) P. Primary interlock switch Y. Cavity lamp (145ºC), closes at 158ºF (70ºC) Q. Relay control board Z. Hood/light switch E. Waveguide thermostat—opens at R. Line fuse (20 amp) AA. Humidity sensor S. Fuse holder BB. Cavity thermostat—opens at 329ºF 257ºF (125ºC), closes at -63.4ºF (-53ºC) T. Hood exhaust fan motor F. AC line filter U. Hood (cooktop) lamps (165ºC), closes at -22ºF (-30ºC) G. Relay board V. Base thermostat—closes at 140ºF CC. Door control assembly (back view) H. Magnetron thermistor I. Magnetron (60ºC), opens at 104ºF (40ºC) (includes touch panel board only) J. Secondary interlock switch DD. UIB (user interface board) K. Ferrite ring EE. LCD module

Primary, Secondary, and Monitor Interlock Switch Checkout Procedure

Switch Check By Door Open Door Closed + 1. Unplug microwave oven or disconnect power. – + 2. Disconnect the wires at the Primary Interlock Switch. – –

3. Check from the common terminal (brown wire) to the normally open

Primary terminal (brown/white wires).

Interlock 1. Unplug microwave oven or disconnect power.

2. Disconnect the wires at the Primary Interlock Switch. +

3. Check from the common terminal (brown wire) to the normally closed

terminal (orange wire).

1. Unplug microwave oven or disconnect power.

Secondary 2. Disconnect the wires at the Secondary Interlock Switch. –

Interlock 3. Check from the common terminal (blue wire) to the normally open

terminal (white/blue wires).

1. Unplug microwave oven or disconnect power.

Monitor 2. Disconnect the wires at the Monitor Interlock Switch. +

Interlock 3. Check from the common terminal (blue wire) to the normally closed

terminal (white/red wires).

(+) Continuity (-) No Continuity

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

(NO) (NC) (NO) (NO) (NC) (NO)

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

TROUBLESHOOTING

Do not continue with the diagnostics of appliance if the 2. All testing must be done with an ohmmeter having a household fuse is blown, a circuit breaker is tripped or if there sensitivity of 20,000 ohms per volt DC or greater, and is less than 120-volt power supply at the wall outlet. powered by at least a 9-volt battery.

Complete the following steps before checking microwave 3. All operational checks using microwave energy must be oven circuitry: done with the microwave oven loaded with a minimum of 8 oz (250 mL) of water in a microwave-safe container. 1. Unplug microwave oven or disconnect power.

Inverter and Magnetron Circuit

L Relay Board Waveguide BK Filter MW Relay Thermostat BU Filter N W BR BR BR 2 4903 1 BK BU BU BU

Fuse Secondary Cavity 20 Amp Primary Ribbon P56 Interlock Thermostat Interlock Cable 10 Switch Magnetron Switch P66 Ribbon CN702 R Cable R Inverter Relay Control Board CN703

CN701 1 23 3 21

P65

Halogen Grill Heater Circuit

Grill Thermostat Secondary

L Grill Relay Interlock Cavity N 4914 Switch W BK Filter BR Thermostat Filter W Relay Board BR WR W2 1W BU BU BU

Fuse Primary Interlock Halogen Grill Waveguide 20 Amp Switch Element Thermostat

Quartz Grill Heater Circuit

Grill

Fuse Thermostat Heater Relay Secondary Interlock Cavity Thermostat L 20 Amp Quartz Grill Element 4904 Switch N BK BR Filter W Filter BR WR W BU BU BU W BU BU BU 2 1

Primary Interlock Relay Board Waveguide Thermostat

Switch

Softstart Quartz Tube Circuit

Fuse Grill Secondary Interlock Cavity 20 Amp Thermostat BR L Halogen Grill Element Switch Thermostat N BK W Filter BR WR BU W BU BU BU Filter W

BK Softstart Relay Waveguide

Primary Interlock BK 2 4924 BK Thermostat Switch 1

Softstart Quartz Tube Relay Board

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Hood Exhaust Fan On (Variable Speed)

Relay Board

Fuse

W 2P82 W 500mA HF R BR 4P54 4170 7P81 5P81 BK W R Motor Inverter R R Capacitor HF Triac

3P82 8P81

BK BK 1P54 3P81 1P82

7190

Waveguide

Fuse Thermostat Filter N 20 Amp W L BR P51 P52 G BU BU BU

Filter BR BR Relay Board Cavity

BK Thermostat

Cooling Fan Motor Circuit

1P83 BU CF 2P53 2P83 BU 4P53 CF Relay BR Fuse 4901 Waveguide 20 Amp Thermostat L Filter N Filter BR BR P52 G BU BU BU W P51 BK Relay Board

Cavity Thermostat

Turntable Motor Circuit

W R

TT 1P53 TT Relay 4906 Fuse W 6P81 Cavity Relay Board L 20 Amp 5P81 BR 4P54 Thermostat Filter N Filter P51 W BR BR BR P52 G BU BU BU BK

Primary Waveguide Interlock Switch Thermostat

Door Open—Oven Cavity Light is On

L Fuse BR Relay Board Waveguide BK 20 Amp BR Filter Fuse Thermostat BU Filter N BR Primary 4170500mA W Interlock P51 G BU BU P52 Switch Fuse Inverter 500mA Cavity

4121 Thermostat

1P55 2P55 3P55

OR

1P62 12 3 12 Cavity P61 P63 Lamp

Relay Control Board

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Cooktop Light On (Variable Light)

L Fuse Waveguide Cavity BK Thermostat Filter 20 Amp 4170 Inverter BU Thermostat Filter N W BR BR BR P51 G BU BU

P5 2 2P81 W Fuse W W 2P84 TR

500mA 1P81

TR

21 Y HL HL P58

Relay Board W Y

1P84

Hood Exhaust Fan On Auto

Motor

Fuse 7P81 W Capacitor

L 20 Amp 8P81 BK Filter BR BR BR BR R W RR P51 W 4 P54 5P81 2P82 R

Relay Control HF

Board BU BU BU BK 3P82

P52 4P81

Base 1P82

Thermostat Filter N W G BU BU BU

Waveguide Cavity Thermostat Thermostat

Troubleshooting Circuit Test Chart

Cooking Mode Magnetron Grill Elements Cooling Fan Hood Exhaust Fan

Microwave only On On

Grill On On On

Microwave and Grill Combination On On On On

NOTE: After grill element is on, the cooling fan and hood exhaust fan may be on for up to 10 minutes for cooling.

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Touch Panel

Touch Panel and Relay Control Board Tests

To access the test mode: Screen Display Display Explanation 1. Unplug microwave oven or disconnect power. 2. Open the microwave oven door. Hood Key Hood key number 3. Press and hold OFF/CANCEL. 4. Plug in microwave oven or reconnect power. Touch panel board Touch panel error 5. Release OFF/CANCEL and close microwave oven door. NOTE: If the OFF/CANCEL key is pressed during this EEPROM Version number of PB (relay diagnostic routine, you will exit the test mode. control board) EEPROM (Electrically Erasable Test Mode Table Programmable Read-Only Memory) Screen Display Display Explanation

UIB SW ver Version number of UIB (user MW reply error MW relay error interface board) software

PB SW Ver Flash Version number of power board Smps FB error Smps feedback error (relay control board) software

Hum sensor error Humidity sensor error

UIB thermistor (ºC) The temperature (ºC) measured by UIB thermistor—ranges about 5ºC above room Cavity thermistor error Cavity thermistor error temperature, if oven has not been used recently Magnetron thermistor error Magnetron thermistor error

Magnetron thermistor (ºC) The temperature (ºC) measured EEPROM error EEPROM (Electrically Erasable by magnetron thermistor— Programmable Read-Only maximum 125ºC Memory) error

HUM PWM Humidity level inside unit— ranges between 8,000 and 8,500, depending on humidity level in oven cavity

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Microwave Oven Power Output Test

1. Place 8 oz (250 mL) of lukewarm water in the center of the NOTE: If the water takes longer than 2 minutes to heat, microwave oven. this may indicate either the operating voltage is lower than 110 volts or there is a problem with the microwave 2. Operate on HIGH power level for 2 minutes. Water oven. should be hot.

NOTE: Many of the problems listed in the chart below may be solved by power cycling: unplug microwave oven or disconnect power. After one minute, plug in microwave oven or reconnect power.

Failure Codes Indications

Display Likely Failure Condition Recommended Repair Procedure

F1.E1 Relay control board 1. Unplug microwave oven or disconnect power. defective 2. Replace the relay control board. 3. Plug in microwave oven or reconnect power.

F2.H1 Hood keys stuck 1. Unplug microwave oven or disconnect power. 2. Replace hood/light switch. 3. Plug in microwave oven or reconnect power.

F2.H2 Hood/light switch defective 1. Unplug microwave oven or disconnect power. 2. Replace hood/light switch. 3. Plug in microwave oven or reconnect power.

F2.Q1 Not reading keypad inputs 1. Unplug microwave oven or disconnect power. 2. Replace the user interface board (UIB). 3. Replace the door control assembly. 4. Plug in microwave oven or reconnect power.

F3.H1 Humidity sensor 1. Unplug microwave oven or disconnect power. 2. Check connection to relay control board. 3. Replace humidity sensor. 4. If problem persists, replace relay control board. 5. Plug in microwave oven or reconnect power.

F3.T1 UIB (user interface board) 1. Unplug microwave oven or disconnect power. thermistor 2. Check the connections from the UIB to the relay control board. 3. If problem persists, replace relay control board. 4. If the problem persists, replace the UIB. 5. Plug in microwave oven or reconnect power.

F3.T4 Magnetron thermistor 1. Unplug microwave oven or disconnect power. 2. Check magnetron thermistor connection. 3. Replace the magnetron thermistor. 4. If problem persists, replace the relay control board. 5. Plug in microwave oven or reconnect power.

F6 MW relay 1. Unplug microwave oven or disconnect power. 2. Check the cable from P85 to inverter. 3. Check to see if the relay (4903 on relay control board) contact has welded

closed. 4. If problem persists, replace relay board. 5. If there is still a problem, replace relay control board. 6. Plug in microwave oven or reconnect power.

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Failure Codes Indications

Display Likely Failure Condition Recommended Repair Procedure

F7 Power to magnetron 1. Unplug microwave oven or disconnect power.

interrupted 2. After 40 seconds, check to see whether this solves the problem.

3. Check cooling fan operation.

4. Check the magnetron.

5. Check P65 connection on the relay control board.

6. Check the P56/P66 connection between relay board and relay control board.

7. Check wiring to the 1100W inverter and control system. See “Checking

Inverters.”

8. Check operation of all interlock switches.

9. Check voltage at 4903-1 on relay board. If it is 120, replace inverter. After

replacing inverter, if there is no voltage, replace relay control board.

10. Plug in microwave oven or reconnect power.

F9 Relay control board 1. Unplug microwave oven or disconnect power.

communications error 2. Check the communications cable from P66 to P56 between relay control

board and relay board.

3. If problem persists, replace the relay board and relay control board.

4. Plug in microwave oven or reconnect power.

F9.Q Touch communication 1. Unplug microwave oven or disconnect power. 2. Check the communications cable from UIB to the touch panel board. 3. If problem persists, replace the door control assembly. 4. Plug in microwave oven or reconnect power.

Component Tests

IMPORTANT:

s Unplug microwave oven or disconnect power. s Conduct a microwave energy test after performing any tests or repairs to the microwave oven. s Remove the lead wires from the related component before conducting any of the following tests. s Check that all wire leads are in the correct position before operating the microwave oven. s Discharge the high-voltage capacitor and remove the lead wires from the primary winding of the high-voltage s Grasp wire connectors when removing the wire leads transformer before conducting any of the following from microwave oven parts. tests. s All testing must be done with an ohmmeter having a s All operational checks using microwave energy must be sensitivity of 20,000 ohms per volt DC or greater, and done with the microwave oven loaded with a minimum powered by at least a 9-volt battery. of 8 oz (250 mL) of water in a microwave safe container.

Components Tests/Results

Magnetron 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. Check that the seal is in good condition. 3. Measure resistance:

s Filament terminals: Normal: Less than 1 ohm s Filament to chassis: Normal: Infinite

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

s Normal: 41 +/- 5 ohms s Abnormal: Infinite

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

s Normal: 2.2k +/- 0.5k ohms (approximate) s Abnormal: Infinite

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Components Tests/Results

Hood Exhaust Fan Motor 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. W 3. Measure resistance: BK R s Pins 1 and 2: Normal: 17 +/- 5 ohms; Abnormal: Infinite 12 3 s Pins 1 and 3: Normal: 21 +/- 5 ohms; Abnormal: Infinite

AC Line Filter 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. P34 P33 3. Measure resistance:

P31 P32 s P31 and P32, P33 and P34: Normal: Great than or equal to 300k ohms; Abnormal: Less than or equal to 100k ohms Humidity Sensor s P31 and P34, P32 and P33: Normal: 0 ohms; Abnormal: Greater than 100k ohms 1 BK 2R 1. Unplug microwave oven or disconnect power. 3W 2. Remove the 3-pin connector from Relay Control Board. 3. Measure resistance across pins 1 and 3, and across pins 2 and 3: Y/G s Normal: 2.8k ohms (approximate) at 77º +/- 10ºF (25º +/- 10ºC) s Abnormal: Infinite

Thermostats NOTE: Refer to “Parts Layout” for opening and closing temperatures.

1. Unplug microwave oven or disconnect power.

Grill / Cavity / Waveguide 2. Remove wire leads.

Thermostat 3. Measure continuity:

Base s Grill, Cavity and Waveguide Thermostats: Normal: Continuity; Abnormal: Infinite Thermostat s Base Thermostat: Normal: Infinite; Abnormal: Continuity

Halogen Grill Element 1. Unplug microwave oven or disconnect power. 1000W, 120V (inside cavity) 2. Remove wire leads. 3. Measure continuity (ohmmeter scale: Rx1):

s Normal: 2 +/- 1 ohms s Abnormal: Infinite

Softstart Quartz Tube 1. Unplug microwave oven or disconnect power. 600W, 60V (not visible to user) 2. Remove wire leads. 3. Measure resistance (ohmmeter scale: Rx1):

s Normal: 6 +/- 2 ohms s Abnormal: Infinite

Quartz Grill Heater 1. Unplug microwave oven or disconnect power. 2. Remove wire leads.

3. Measure resistance: s Normal: 29 +/- 5 ohms s Abnormal: Infinite

Magnetron Thermistor 1. Unplug microwave oven or disconnect power.

2. Remove wire leads.

3. Measure resistance: s Normal: 10k +/- 5% ohms at 77ºF (25ºC) s Abnormal: Infinite

Motor Capacitor 1. Unplug microwave oven or disconnect power.

2. Remove wire leads. 3. Measure resistance:

s Normal: Momentarily 0 ohms, then goes to infinite s Abnormal: Infinite

Cavity / Hood Lamp 1. Unplug microwave oven or disconnect power. 2. Remove wire leads.

3. Measure resistance: s Normal: 1.5 +/- 0.5 ohms s Abnormal: Infinite

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Components Tests/Results

Relay Control Board NOTE: Do not try to repair or make adjustments to the relay control board. 1. Unplug microwave oven or disconnect power. 3121 1 P74 P73 P71 1 P67 2. Check wiring to relay control board. 1 P62 1 P61 3. Visually inspect P61, P62, P63, P64, P65, P66, P67, P68, P71, P73 and P74 to see 6152 P63 1 P66 whether there are signs of overheating or any signs of failure due to loose wires, bad 7001 1 P65 4625 crimping, etc. 1 P68 NOTE: Do not try to repair or make adjustments to the hood/light switch. 11 P64 1. Unplug microwave oven or disconnect power. 2. Check wiring to hood/light switch. Hood / Light Switch 3. Visually inspect P21 to see whether there are signs of overheating or any signs of

P21 failure due to loose wires, bad crimping, etc.

4501 P22 4502 4503

Relay Board NOTE: Do not try to repair or make adjustments to the relay board. 1. Unplug microwave oven or disconnect power. P57 4905 2. Check wiring to relay board. 4924 3. Visually inspect P51, P52, P53, P54, P55, P56 and P57 to see whether there are signs 1 P58 1 P56 4903 4904 49324931 4914 of overheating or any signs of failure due to loose wires, bad crimping, etc. 5174 5170 3191 P52

P53 1 P51 1 4907 4901 4170 P54 4906 P54 3110

4121 1

Checking Inverters

Measure Oven Input Current If more than 0.5A: The 1100W inverter is probably OK. Check the magnetron. 15A See Magnetron test in “Component Tests.”

Amps If less than 0.5A: There is no input to the 1100W inverter. Connect an ammeter (Valhalla Scientific 2101 or equivalent Check the following: recommended) to measure the input current of microwave s No AC voltage supply. Check relay control board and oven when the power level is set to Level 10 at the touch panel. wiring. s No control signal. Check relay control board and wiring. Check the 1100W Inverter NOTE: Do not try to repair the inverter board, nor try to make A B any adjustments to the board.

H C Check wiring to 1100W inverter: 1. Unplug microwave oven or disconnect power. 2. Visually inspect 4 connectors on the 1100W inverter

board, CN701, CN702, CN703, E701, to see whether there are signs of overheating or any signs of failure due to loose wires, bad crimping, etc.

G D

F E

A. CN702 E. CN703 B. Heat sink F. Control signal in/out C. E701 G. CN701 D. High-voltage output to H. 120V AC

magnetron

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8205280 / 4619-651-98881 9/05 FOR SERVICE TECHNICIAN’S USE ONLY