tech-sheet-8204949
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 b. Make the following safety checks on all ovens to be repaired, replaced, or adjusted by procedures serviced before activating the magnetron or other described in service manual before the oven is microwave source, and make repairs as necessary: released to the 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 & Other f. Do not attempt to operate the oven if the door glass is Damage) broken.

4. Damage to or Loosening of Hinges & 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.

Microwave Oven Power Output Test

The power output of the magnetron can be measured by the 3. When finished, stir the thermometer through the water following tap water temperature rise test. and record the temperature. NOTES: s Be sure oven cavity is clean and cool (not used recently). 4. Subtract the cold water temperature from the warm water temperature to get the temperature rise. Normal range is s Line voltage at the wall outlet less than 120 volts will as shown in the following table. lower the magnetron output. Voltage Temperature Rise 1. Fill a glass beaker with 32 oz (946 mL) of tap water. Stir (VAC under load) the water with a thermometer (digital recommended) and ºF ºC record the temperature. This starting temperature of the 120V water should be between 50ºF and 75ºF (10°C and 24°C). 108V 24 – 27 13 – 15

2. Place the beaker and water in the center of the 20 – 22 11 – 12 microwave oven. Operate on HIGH power level for 60 seconds.

Models: 665.63792302 665.63793302 665.63794302 665.63799302 FOR SERVICE TECHNICIAN’S USE ONLY

8204949 / 4619-651-97952

Failure Codes Indications

Displ Likely Failure Recommended Repair Procedure

ay Condition

F0 No error None

F2K Key or foil 1. Unplug microwave oven or disconnect power.

pressed more 2. Replace membrane switch. than 1 minute 3. If problem persists, replace power supply board.

4. Plug in microwave oven or reconnect power.

F2T Touch panel 1. Unplug microwave oven or disconnect power.

pressed more 2. Replace the display module. than 1 minute 3. If problem persists, replace power supply board.

4. Plug in microwave oven or reconnect power.

F3H Humidity 1. Unplug microwave oven or disconnect power.

sensor out of 2. Connect a new sensor to the board (at P3). range 3. Plug in microwave oven or reconnect power.

4. If problem persists:

s Unplug microwave oven or disconnect power.

s Replace power supply board.

5. Plug in microwave oven or reconnect power.

F3T Temperature 1. Unplug microwave oven or disconnect power.

sensor out of 2. Replace power supply board. range 3. Plug in microwave oven or reconnect power.

F7 Power to 1. Unplug microwave oven or disconnect power. 2. After 40 seconds, check to see whether this solves the problem. (Possible reason: Over magnetron temperature protection for the magnetron opened.) interrupted 3. Check resistance of the magnetron thermostat. It should be close to 0 ohms. 4. Check the magnetron. 5. Check wiring to the 1100W inverter and control system. 6. Check operation of all interlock switches. 7. If switches operate correctly:

s Replace 1100W inverter.

s If problem persists, replace power supply board.

8. Plug in microwave oven or reconnect power.

F9M E2PROM 1. Unplug microwave oven or disconnect power. missing 2. Replace power supply board. 3. Plug in microwave oven or reconnect power.

F9E E2PROM 1. Unplug microwave oven or disconnect power. empty 2. Replace power supply board. 3. Plug in microwave oven or reconnect power.

F9C E2PROM 1. Unplug microwave oven or disconnect power. CheckSum 2. Replace power supply board. error 3. Plug in microwave oven or reconnect power.

F9W E2PROM write 1. Unplug microwave oven or disconnect power. error 2. Replace power supply board. 3. Plug in microwave oven or reconnect power.

F10 Display error 1. Unplug microwave oven or disconnect power.

2. Check that the ribbon cables between the display module and the microcomputer board at

P11 and P21 are securely connected.

3. If problem persists, replace power supply board.

4. Plug in microwave oven or reconnect power.

NOTE: If lights work, but cooling fan does not, 40W inverter might have failed. See “Checking Inverters.”

2

FUSE INTERLOCK 5OR 20 Amp 28R 8OR SECONDARY 29BK

HUMIDITY 30BU Quartz Heater 32BR SENSOR Grill Thermostat

7R Halogen Grill Element 1BR 33BK 31BK

BK Softstart Quartz Tube R 120V/60Hz W 35R 34W 1 28R BK 2P0 Y/G 43Y/G 32BR WIRING DIAGRAMS 19BU 1

L 9Y

P3 1 DISPLAY PCB MW 46W/3C 1 P4 & POWER PCB Relay P2 GND G 1 GND 1 P27 Control 4903 CN701 N CN1 P26 Inverter 45W/3C INV TT Softstart Grill Heater 1100W Schematic Diagram 40W CN151 48W/2C 17BK DC Fan Relay Relay Relay Relay INVERTER W INVERTER Relay 4916 4906 4915 4914 Relay 2 1P0 4917 4904 CN702 CN152 CN703 1 CN153 2 2 2 E701

2BU 1 1 7911

15R 1 1 1 1 54R 55R

Cavity 22Y PK R 1 5OR 37W Thermostat-1 21W PK CL BK 12Y CF 19BU N1 INV TT L1 DOOR HF 36BK 56GY Cavity 5P11 P14 1 GND Thermostat-2 3BU 20R 27OR 42Y/G Cavity 6P11 52BR 53BK 41Y/G Thermostat-3 1P11 2P11 51G FUSE 27OR Filter 50W 49W 16G 4 Amp SM Capacitor BK 13W MAGNETRON 25BU 26BU 1P10 14W Exhaust Fan 11BR 38BU 24W Y Y HF BK 15R Motor Thermostat TR 2P10 23W TR 9Y Capacitor 57GY INTERLOCK BK 10BR FUSE 4BU 3P10 HL PRIMARY 58GY TT 40W INTERLOCK 4 Amp Magnetron HL MONITOR 39BU Thermostat

18BU

CONDITION: DOOR OPEN SM STIRRER MOTOR CF COOLING FAN MOTOR P2/P3/P4/P14/P26/P27/CN1/CN151/CN152/ 1BR SYMBOL NOTES TT TURNTABLE MOTOR (DC FAN MOTOR) CN153/CN701/CN702/CN703: WIRE COLOR-BROWN WIRE TO PCB CONNECTORS WIRE NO.-1 CL CAVITY LAMP P0/P10/P11: WIRE TO WIRE CONNECTORS 45W/3C RIBBON CABLE/3Core

BK: BLACK W: WHITE BR: BROWN DWG.NO. MU-064 OR: ORANGE HL HOOD LAMP BU: BLUE G: GREEN GY: GRAY (COOKTOP LAMP) PK: PINK HF HOOD EXHAUST FAN MOTOR R: RED Y: YELLOW

TR: TRANSPARENT

3

1W BU BU BU BU INTERLOCK INTERLOCK BK CAVITY CAVITY MONITOR SWITCH PRIMARY SWITCH 4 G BR THERMOSTAT 1 CAVITY THERMOSTAT 3 THERMOSTAT 2 BR FUSE & BU POWER CORD TWO POLES RIBBON CABLE/2C Y/G FUSE HOLDER BK HUMIDITY CONNECTOR (P0) SENSOR OR W W Y/G R CN153 MAGNETRON BK THERMOSTAT BU 1 BU

CAVITY LAMP & PK 1 INTERLOCK PK SUPPORT DISPLAY PCB CAVITY LAMP CN152 R OR Y BR P3 BU HOLDER 1 GY GY MCU 40W INVERTER 7001 7000 CN1 RIBBON CABLE/3C CN151 GY R GRILL THERMOSTAT 1 OR Y R INTERLOCK P4 1 DC FAN W SECONDARY MOTOR SWITCH BK P2 SIX POLES R GY BU Pictorial Diagram 1 CONNECTOR OR

RIBBON CABLE/3C (P11) 1 6 6 Y/G P22 1

P21 P11 234 5 BU 234 5 FILTER 1 1 CAPACITOR 1 1 TR BU BU BK GY P21 RIBBON CABLE/2C P11 Y W W GY

P27 P26 BK HOOD LAMPS & BR HOOD LAMP HOLDERS BK 4903 POWER PCB 1 R TURNTABLE MW 1 TR MOTOR BU RELAY Y BK STIRRER BU R 4904 OR MOTOR R HEATER BK DC FAN 4917 BK RELAY RELAY RIBBON CABLE/3C

4914 OR OR GRILL RELAY R R CN701

4915 INV TT R 1 SOFTSTART RELAY RELAY BR BR RELAY 4916 4906 FUSE & FUSE & BK CN702 FUSE SADDLE FUSE SADDLE 4915 G 1 1 BK BU INVERTER 4903 4904 4914 G 2 2 BK BU BR 3 3 BK R 2 W EXHAUST FAN 2 2 2 THERMOSTAT W R 1100W BU 1 BU OR BK 1 1 1 P14 BU

1 R Y ORRW R THREE POLES

RBRBK CONNECTOR HOOD EXHAUST BU (P10) FAN MOTOR BUW MAGNETRON

BK Y W MOTOR R CAPACITOR

BK W

DWG.NO. L-M1-060 HALOGEN GRILL ELEMENT

R W CN703 W SOFTSTART QUARTZ TUBE BU BU OR Y/G

BR QUARTZ HEATER BU BU BU

R R R

Pictorial Diagram

DISPLAY PCB LIGHT SENSOR ENCODER 1 P26 P12 1 P25 1

LCD MCU 1 W HUMIDITY MODULE P8 7001 P13 R P3 7000 BK SENSOR RIBBON CABLE/3C 1

RIBBON 1 40W CABLE/3C J2 1 INVERTER 1 P11 EXTERNAL RIBBON P4 1 Y/G CN151 KEYBOARD CABLE/4C 1

P7 P2 1 1100W P11 INVERTER LCD P9 P7 1 1 MODULE Y/G P22 1 BK CN701 P21 R P6 1

TOUCH PANEL 1 P21 (MEMBRANE P27 P26 SWITCH)

RIBBON

LCD J3 A CABLE/3C

MODULE K P25 VLCD

40W RIBBON DC FAN INVERTER CABLE/2C MOTOR

CN153 1 1 1

POWER PCB DC FAN RELAY

4917

TURNTABLE OR MW Heater Grill Softstart INV TT MOTOR R Relay Relay Relay Relay RELAY RELAY 4903 4904 4914 4915 INTERLOCK R 4916 4906 SECONDARY BK 2 2 2 2

SWITCH 1 1 1 1 P14

1100W 1 INVERTER BR W OR STIRRER BK Y MOTOR BR

R

BU G

R W

BU

HEATER QUARTZ INTERLOCK SECONDARY SWITCH

EXHAUST FAN THERMOSTAT

TURNTABLE MOTOR

40W INVERTER

FUSE 4 AMP.

SOFTSTART QUARTZ TUBE

MAGNETRON THERMOSTAT

DWG.NO. L-M1-061

5

Parts Layout

(not to scale)

D E C FG B HI J A K CC L BB M V N O

P

AA Q ZY

X R W UT S

V

A. Grill thermostat—opens at 293ºF (145ºC), manual resets at O. Magnetron (8183990) 239ºF (115ºC), auto resets at -4ºF (-20ºC) (8184840) P. 1100W inverter (8183997) Q. 40W inverter (8184952) B. Cavity thermostat 1 assembly—opens at 329ºF (165ºC), R. 12V cooling fan motor (8184875) closes at -31ºF (-35ºC) (8183999) S. Filter capacitor (8184093) T. Exhaust fan thermostat—opens at 104ºF (40ºC), closes at C. Halogen grill element (8184837) D. Humidity sensor (4393808) 140ºF (60ºC) (8183998) E. Softstart quartz tube (8184838) U. Fuse (4 amp.) (8184579) F. Quartz heater (8184839) V. Hood (cooktop) lamp (8169418) G. Stirrer fan motor (4393746) W. Membrane switch/control panel/display lens (WT-8184842, H. Cavity thermostat 2 assembly—opens at 257ºF (125ºC), BK-8184843, BI-8184844, SS-8184845) closes at -31ºF (-35ºC) (8184585) X. Power supply board (microcomputer) (8184841) I. Line fuse (4393308) Y. Secondary interlock switch (4393697) J. Fuse holder (4393538) Z. Monitor interlock switch (4393598) K. Hood (exhaust) fan motor (8184876) AA. Primary interlock switch (4393599) L. Motor capacitor (8184092) BB. Turntable motor (4393755) M. Cavity thermostat 3 assembly—opens at 257ºF (125ºC), CC. Caviy lamp (8169418)

closes at -31ºF (-35ºC) (8184586) N. Magnetron thermostat—opens at 257ºF (125ºC), closes at

185ºF (85ºC) (8184951)

PRIMARY, SECONDARY, AND MONITOR INTERLOCK SWITCH CHECKOUT PROCEDURE

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

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

open terminal (white wire).

1. Unplug microwave oven or disconnect power.

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

3. Check from the common terminal (orange/yellow wires) to the

Secondary normally open terminal (red/black wires).

Interlock 1. Unplug microwave oven or disconnect power.

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

3. Check from the common terminal (orange/yellow wires) to the

normally closed terminal (orange wire).

(+) Continuity (-) No Continuity

6

PRIMARY, SECONDARY, AND MONITOR INTERLOCK SWITCH CHECKOUT PROCEDURE

Switch Check By Door Open Door Closed

Monitor 1. Unplug microwave oven or disconnect power.

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

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

closed terminal (yellow/brown wires).

(+) Continuity (-) No Continuity

NOTE: These diagrams are not intended to show a complete Touch Panel Continuity Diagram circuit; they represent the position of switches during “DOOR OPEN” or “DOOR CLOSED” (continuity checks only). PIN# 9 10 11

Door Closed TURNTABLE CLOCK ON/OFF POPCORN L N 1 START (NC) (NO) (NO) (NC) (NC) (NO) STOP 2 CLEAR SECONDARY MONITOR PRIMARY INTERLOCK SWITCH INTERLOCK KITCHEN TIMER

SWITCH SWITCH 3 SET/OFF

Door Open

L (NC) (NO) (NO) (NC) (NC) (NO) N 4

SECONDARY MONITOR PRIMARY 5

INTERLOCK SWITCH INTERLOCK

SWITCH SWITCH

6

Touch Panel COOKTIME 7 POWER

Example of use: When TURNTABLE ON/OFF is selected, a ADD ONE MINUTE resistance of less than 200 ohms will be observed between 1

and 10 on the flex circuit connector. See “Touch Panel 8

Continuity Diagram.”

18 Pin Flex Circuit Connector ESD GROUND PLANE

1 18 12 13 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 14 15 16 17 18

Touch Panel and Microcomputer Board Test

The microwave hood combination is provided with a self- Test Mode Table diagnostic routine that can be accessed through the touch keypad. Screen Display Display Explanation Program Version To access the test mode: Oven Status Version number

1. Press the clock key. Stop Reason Current Error (if any) e.g., F0=No Error. See “Failure Code/Indications.” 2. Touch “Hours” on the touch screen and set hours to “1.” Humidity Temperature Reason cooking cycle interrupted. 3. Touch “Minutes” on the touch screen and set minutes to Night Light See “Stop Reason Table.” “23.” Normal range: 8191-28671 4. Select “AM.” Normal range: 46-100 5. Touch “1:23” on the touch screen. You are now in the test mode. The screen display will appear as shown in the Range: 0-255 “Test Mode Table.” Varies depending on ambient light. Value should be near 0 when light NOTE: If the STOP/CLEAR button is pressed during this sensor opening is covered. diagnostic routine, you will exit the test mode.

7

Stop Reason Table Code Displayed Last Stop Reason 4 Inverter error “Stop Reason” displays how the last run cooking cycle was 5 Humidity sensor error stopped. The table below lists all possible codes. 6 Temperature sensor error 7 Touchfoil error Code Displayed Last Stop Reason 8 Oven overheated 0 Power reset 9 Oven overheated 1 Door opened FF No cooking cycle stopped 2 Cook time elapsed 3 Cancel key pressed

TROUBLESHOOTING

Complete the following steps before checking microwave 3. All testing must be done with an ohmmeter having a oven circuitry: sensitivity of 20,000 ohms per volt DC or greater, and powered by at least a 9-volt battery. 1. Unplug microwave oven or disconnect power. 4. All operational checks using microwave energy must be 2. Do not continue with the diagnostics of appliance if the done with the microwave oven loaded with a minimum of fuse is blown, a circuit breaker is tripped or if there is less 10 oz (300 mL) of water in a microwave-safe container. than 120 volts at the wall outlet.

Microwave cooking

MICROCOMPUTER BOARD

FUSE DISPLAY PCB & POWER PCB FUSE

4 AMP 4 AMP

BR BR BR 4P14 CONTROL G G BK INVERTER 1P14 Y GND Y/G OR 5P14 TTM RELAY STIRRER MOTOR

BU 5P11 R 3P14 4906 3.3-4.2k MAGNETRON THERMOSTAT BK SM GY

INTERLOCK TURNTABLE SECONDARY TT MOTOR FILTER CAPACITOR INTERLOCK CAVITY SWITCH 2.7-3.8k PRIMARY THERMOSTAT 3 BU 6P11 OR SWITCH L1 MW RELAY R GY BK 4903 BR OR R 2 1 R GY BU W BU BU

2P0 R BU 2P14 FUSE 20 AMP 12 INVERTER RELAY RIBBON MAGNETRON CAVITY CN1 CABLE/3C CN702 W PK 1100W CN703RIBBON4916 THERMOSTAT 2

CN701CABLE/3C W BU 12 3 3 21 N BU W P2 1P0 P4 1 234

1 234 1 2 CN151 CN153

CN152 12 PK INVERTER CAVITY E701 Y/G CAVITY 40W RIBBON DC FAN RELAY THERMOSTAT 1 LAMP INVERTER CABLE/2C 1P27 4917 1P26 R CF DC FAN

Y/G GND 2P27 2P26 BK MOTOR

Microwave and grill combination cooking

MICROCOMPUTER BOARD FUSE HOOD EXHAUST 4 AMP FAN MOTOR FUSE DISPLAY PCB & POWER PCB 4 AMP Y BR BR BR 4P14 1P14 G G CONTROL INVERTER W 2P10 BK

6P14 Y R 3P10 BK HF BK BK W 1P10 OR 5P14 HF TRIAC 7911 STIRRER

TURNTABLE TTM RELAY MOTOR MOTOR 4906 3.3-4.2k INTERLOCK MOTOR BU 5P11 R SM CAPACITOR MAGNETRON SECONDARY 2.7-3.8k 3P14 THERMOSTAT SWITCH FILTER INTERLOCK CAVITY FUSE THERMOSTAT 3 20 AMP TT 6P11 BK CAPACITOR GY PRIMARY SWITCH L1 OR BU OR MW RELAY R GY BK BR 4903 R R GY BU W BU BU 2 1

2P0 R BU 2P14 RIBBON BU CABLE/3C W MAGNETRON BK INVERTER RELAY CAVITY CN702 THERMOSTAT 2 CAVITY LAMP CN70312RIBBON4916 PK CN1 BU CN701CABLE/3C1100W W 12 3 PK 3 21INVERTER CAVITY Y/G THERMOSTAT 1 P2 E701 P4 1 234

1 234 1 2 CN151 CN153

CN152 12 GRILL 40W RIBBON DC FAN RELAY 1P26 R N THERMOSTAT INVERTER CABLE/2C 1P27 4917 2P26 BK BU W

CF DC FAN 1P0 MOTOR Y/G GND 2P27 HEATER RELAY 2 4904 QUARTZ HEATER BR BU 1 BK W HALOGEN GRILL ELEMENT Y/G GRILL RELAY GND 4914 BK BK BU W2 SOFTSTART QUARTZ TUBE 1

SOFTSTART RELAY

4915

R 2 1 BK

8

Grill cooking

FUSE MICROCOMPUTER BOARD FUSE 4 AMP DISPLAY PCB & POWER PCB 4 AMP

Y BR BR BR 4P14 CONTROL 1P14 G G

INVERTER

OR 5P14 6P14 Y W HOOD EXHAUST W FAN MOTOR TURNTABLE MOTOR HF TRIAC 7911 2P10 BK

INTERLOCK 2.7-3.8k TTM RELAY R 3P10 BK HF BK SECONDARY 1P10 R OR BU TT BU R 3P14 4906 SWITCH 6P11 5P11 MOTOR FUSE L1 20 AMP HEATER RELAY CAPACITOR BK BK BR 2P0 OR BK QUARTZ HEATER BR 4904 BK INTERLOCK CAVITY BU PRIMARY THERMOSTAT 3 2 1 SWITCH W GRILL HALOGEN GRILL ELEMENT GRILL RELAY 4914 THERMOSTAT BK BK 1 BU BU W BU BU SOFTSTART RELAY SOFTSTART QUARTZ TUBE W2 4915

R2 1 BK CAVITY GND Y/G THERMOSTAT 2 R BU 2P14 BU INVERTER RELAY CAVITY 12 RIBBON 4916 THERMOSTAT 1 N CN1 CABLE/3C BU W PK 1P0 P4 PK 1 234

1 234 1 2 CN151 CN153

CN152 12 CAVITY 40W RIBBON DC FAN RELAY 1P26 R CF DC FAN LAMP Y/G INVERTER CABLE/2C 4917

GND 1P27 2P26 BK MOTOR 2P27

Blower fan turns on automatically

L1 FUSE FUSE HOOD EXHAUST CAVITY CAVITY BK BR 20 AMP 2P0 4 AMP W FAN MOTOR THERMOSTAT 3 THERMOSTAT 1 OR Y BR BR 2P10 BK

W N

R 3P10 BK HF BK BK BU BU BU BU W

EXHAUST FAN 1P10 CAVITY 1P0 THERMOSTAT MOTOR THERMOSTAT 2

CAPACITOR

Blower fan on

L1 FUSE FUSE MICROCOMPUTER BOARD FUSE 20 AMP 4 AMP DISPLAY PCB & POWER PCB 4 AMP

BK BR OR Y BR BR BR 4P14 CONTROL 1P14 G G INVERTER HOOD EXHAUST 2P0 CAVITY CAVITY

6P14 Y W FAN MOTOR THERMOSTAT 3 THERMOSTAT 1 N Y/G W 2P10 GND BK

HF TRIAC 7911 R 3P10 HF BK BK BU BU BU BU W 1P10 1P0 BK

CAVITY

MOTOR THERMOSTAT 2

CAPACITOR

Microwave plugged in—time of day displayed

MICROCOMPUTER BOARD CAVITY CAVITY

FUSE FUSE THERMOSTAT 3 THERMOSTAT 1

L1 20 AMP DISPLAY PCB & POWER PCB 4 AMP N

BK BR OR Y BR BR BR 4P14 CONTROL 1P14 G G BK BU BU BU BU W 2P0 INVERTER GND Y/G FUSE CAVITY 1P0 4 AMP THERMOSTAT 2

Door open—oven cavity light is on

MICROCOMPUTER BOARD CAVITY CAVITY THERMOSTAT 3 THERMOSTAT 1 FUSE DISPLAY PCB & POWER PCB FUSE 4 AMP 4 AMP N G Y BR BR BR 4P14 CONTROL 1P14 G BK BU BU BU BU W OR INVERTER FUSE CAVITY 1P0

L1 20 AMP 5P14 THERMOSTAT 2

BK BR OR IINTERLOCK INVERTER RELAY SECONDARY 4916 2P0 R SWITCH BU 2P14

12

CN1 RIBBON CABLE/3C PK P4 GND Y/G 1 234 PK 1 234 CN151

CN152 12 CAVITY LAMP 40W INVERTER

Y/G GND

9

Cooktop light on

FUSE MICROCOMPUTER BOARD CAVITY CAVITY 20 AMP THERMOSTAT 3 THERMOSTAT 1 FUSE DISPLAY PCB & POWER PCB FUSE L1 OR N BK BR 4 AMP 4 AMP 2P0 Y BR BR BR CONTROL 4P14 INVERTER 1P14 G G BK BU BU BU BU W

CAVITY 1P0

HOOD LAMPS R BU THERMOSTAT 2 (COOKTOP LAMPS) 12 2P14 CN1 INVERTER RELAY TR W 2P11 4916 40W INVERTER RIBBON CABLE/3C TR W P4 Y/G 1 234 GND Y Y 1 234 Y W 1P11 CN151

CN152 43

Y/G GND

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. 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 All operational checks using microwave energy must be done with the microwave oven loaded with a minimum s Grasp wire connectors when removing the wire leads of 10 oz (300 mL) of water in a microwave safe from microwave oven parts. container.

Components Test Results Magnetron 1. Unplug microwave oven or disconnect Normal: Less than 1 ohm Antenna power. Normal: Infinite Gasket 2. Remove wire leads. Check that the seal is Filament in good condition. DC Cooling Fan Motor 3. Measure resistance (ohmmeter scale: Rx1): s Filament terminal

4. Measure resistance (ohmmeter scale: Rx1k): s Filament to chassis

1. Unplug microwave oven or disconnect Fan should work. If not: power. 1. Unplug microwave oven or disconnect power. 2. Remove wire leads. 2. Replace fan. 3. Using an external 9 or 12 DC voltage source, connect to fan wires: red (R) wire to “+” and black (BK) wire to “-.”

R BK

Turntable Motor/Stirrer Motor 1. Unplug microwave oven or disconnect

power.

2. Remove wire leads. Digital 3. Measure resistance. (ohmmeter scale: COM Meter Turntable Motor Rx1k): s Normal: 2.7k-3.8k ohms (approximately)

s Abnormal: Infinite

Stirrer Motor s Normal: 3.3k-4.2k ohms (approximately)

s Abnormal: Infinite

10

Components Test Results Hood Exhaust Fan Motor 1. Unplug microwave oven or disconnect Normal: BK 2 power. s Black 1 (BK 1) – Black 2 (BK 2): 30-

2. Remove wire leads. 60 ohms (approximately) 3. Measure resistance (ohmmeter scale: s Black 1 (BK 1) – Black 3 (BK 3): 40-

Rx1): 80 ohms (approximately) Abnormal: Infinite BK 3

BK 1 1. Unplug microwave oven or disconnect Humidity Sensor power.

W 3 2. Remove the 3-pin connector from PCBA Normal: 2.8k ohms (approximately) at R 2 (P3). 77º +/- 18ºF (25º +/- 10ºC) 1 NOTE: Do not remove the attached BK resistor, which is used for internal Abnormal: Infinite resistance calibration. Resistor Normal: 2.8k ohms (approximately) at 3. Measure resistance across pins 1 and 77º +/- 18ºF (25º +/- 10ºC) 3 (ohmmeter scale: Rx1k): Abnormal: Infinite 4. Measure resistance across pins 2 and Thermostats 3 (ohmmeter scale: Rx1k):

NOTE: Refer to “Parts Layout” 1. Unplug microwave oven or disconnect for opening and closing power. temperatures. 2. Remove wire leads.

Cavity 3. Cavity, Magnetron and Grill Thermostats: Normal: Continuity Thermostat Measure continuity (ohmmeter scale: Rx1): Abnormal: Infinite

Magnetron 4. Exhaust Fan Thermostat: Measure Normal: Infinite Thermostat continuity (ohmmeter scale: Rx1): Abnormal: Continuity Grill Thermostat 1. Unplug microwave oven or disconnect power. Exhaust Fan Thermostat 2. Remove wire leads. 3. Measure continuity (ohmmeter scale: Rx1): Normal: 1500 ohms (approximately) Halogen Grill Element 1000W, 120V (inside cavity) Abnormal: Infinite

Softstart Quartz Tube 1. Unplug microwave oven or disconnect 600W, 60V (not visible to user) power.

2. Remove wire leads. Normal: 6 ohms (approximately) Abnormal: Infinite 3. Measure resistance (ohmmeter scale: Rx1):

11

Components Test Results

Quartz Heater 1. Unplug microwave oven or disconnect Normal: 27 ohms (approximately) 500W, 120V (inside cavity) power. Abnormal: Infinite

2. Remove wire leads 3. Measure resistance (ohmmeter scale:

Rx1):

Measure oven input current Checking Inverters

15A NOTE: Do not try to repair the inverter board, nor try to make any adjustments to the board. 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 any signs of failure due to loose wires, bad crimping, signs of overheating, etc.

Amps Check the 40W Inverter

Connect an ammeter (Valhalla Scientific 2101 or equivalent B CD recommended) to measure the input current of microwave oven when the power level is set to Level 10 at the touch panel.

If more than 0.5A:

The 1100W inverter is probably OK. Check the magnetron.

See Magnetron test in “Component Tests.” A E If less than 0.5A:

There is no input to the 1100W inverter. Check the following: F s No AC voltage supply. Check power supply board

and wiring. G

s No control signal. Check power supply board and

wiring.

Check the 1100W inverter I H

A B A. 120V main input F. 12V halogen lamps and B. CN1 cavity lamps output C. CN152 D. CN151 G. 12V cooling fan output E. Control signal input H. CN153 I. Heat sink

C NOTE: Do not try to repair the inverter board, nor try to make

H any adjustments to the board.

Check wiring to 40W inverter:

1. Unplug microwave oven or disconnect power.

G 2. Visually inspect 4 connectors on the 40W inverter board,

D CN1, CN151, CN152, CN153, to see whether there are any signs of failure due to loose wires, bad crimping,

signs of overheating, etc.

F E

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

8204949 / 4619-651-97952 2/04 FOR SERVICE TECHNICIAN’S USE ONLY