precautions to be observed before and ......q. hood (cooktop) lights r. hood exhaust fan motor s....
TRANSCRIPT
Tech Sheet Do not discard
W10220004A / 461965199771 FOR SERVICE TECHNICIAN’S USE ONLY
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 open.
b. Make the following safety checks on all ovens to be serviced before activating the magnetron or other microwave source, and make repairs as necessary:1. Interlock Operation2. Proper Door Closing3. Seal and Sealing Surfaces (Arcing, Wear
and Other Damage)4. Damage to or Loosening of Hinges and
Latches5. 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.
d. Any defective or misadjusted components in the interlock, monitor, door seal, and microwave generation and transmission systems shall be repaired, replaced, or adjusted by procedures described in service manual before the oven is released to the owner.
e. A microwave leakage check to verify compliance with the Federal Performance Standard should be performed on each oven prior to release to the owner.
f. Do not attempt to operate the oven if the door glass is broken.
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.
2
WIRING DIAGRAMSSchematic Diagram
DWG
NO
.M
U-1
02-TMagnetron
Rel
ay B
oard
Prim
ary
Inte
rlock
Switc
h
R
R
CN
702
BRFu
se20
Am
p
Y/G
CN
703
E701
Inve
rter
Mon
itor
Inte
rlock
Switc
h
LN
G
W12
0V /
125V
,60H
z
Y/3C
Rib
bon
Cab
le /
3 C
ore
MW
Rel
ay49
03
12TT
TT R
elay
4906
1P5
3
CF
Rel
ay49
01 F
CFA
Rel
ay 4
907
P52N
FCH
Rel
ay49
05
CF
FCF
FC Ring Heater
GN
D
FCTH
CF
FCFA
500m
AFu
se
L
P74
1
FC Te
mpe
ratu
re S
enso
r
BR
RR12
1
Mag
netro
n Se
nsor
Y P81-1Y 1
HL
HL
P81-2
P58
FCTh
erm
osta
tP84-1
P84-2
1
4121
R
P51
P57
P56
P67
P66
1
BK
W
P68
Relay Control Board
Hum
idity
Sens
or
P65
P61
1CN701
Inve
rter
1P5
4
1
P55
P71
CL
1P6
3
1
P62
Doo
rN
FS
Inve
rter
500m
AFu
se41
70
P83-
2
P83-
1L1N
1
P33
P32
Coi
lR
Cy
Cy
CxP3
1P3
4AC
Lin
e Fi
lter
Cx
VDR
VDR
P35
BK
MW RelayFeedback
P85
1
P87
TT
BU
W BK/
R/1
0C
Y/3
C
VDR R/3
C
R
R
R BK
BK
R
W
4931
Rel
ay49
3249
30
PR2
PR1
P64
UIB
G
Y/5C
P2P3
LCD
UIB
Ther
mis
tor
R/8
C
C
olor
/5CP8
636
00
Touc
hPa
nel
Boar
d
P6
BR
P73
1
1
R BK
R
HF
G
Cav
ityTh
erm
osta
tW
aveg
uide
Ther
mos
tat
R
P81-
5
P81-
3
P82-
3RM
otor
Cap
acito
rR
P81-
8R BU
BK
WP8
2-2
P82-
1
P81-
6
P81-7
P81-4Base Thermostat
P81-9
BK
W W
GYGY
RBU
BK
Seco
ndar
yIn
terlo
ckSw
itch
BK
GY
ORBUBR
BR
Y
R
R
BUBKBK
BK
OR
BR
BU
W
W
W
W
TRTR
BKW
ire C
olor
P6-1
Pin
No.
--1C
onne
ctor
Nam
e
Con
ditio
n: D
oor O
pen.
Sym
bol N
otes
:
GY
BR
W
Rel
ayR
elay
Blac
k
BKW
hite
W
Blue
B
UBr
own
BR
Red
RO
rang
e
OR
Yello
w
YYe
llow
/Gre
en
Y/G
Gre
en
G
Gra
y
GY
Hoo
d (C
ookt
op)
Ligh
ts
HF
Hoo
d Ex
haus
t Fa
n M
otor
Cav
ity L
ight
TTTu
rnta
ble
Mot
or
CF
CL
HL
HL
Coo
ling
Fan
Mot
or
FCF
Forc
ed C
onve
ctio
nFa
n M
otor
3
Parts Layout (not to scale)
(+) Continuity (-) No Continuity
A. Waveguide thermostat—opens at 257ºF (125ºC), closes at -95ºF (-35ºC)
B. AC line filter C. Relay board D. Magnetron sensor E. Magnetron F. Secondary interlock switch G. FC thermoactuator H. Ferrite ring I. Inverter J. Cooling fan motor K. Motor capacitor L. Monitor interlock switch
M. Primary interlock switch N. Relay control board O. Line fuse (20 amp) P. Fuse holder Q. Hood (cooktop) lights R. Hood exhaust fan motor S. Power resistor-1 (20 ohm/25 W) T. Power resistor-2 (41 ohm/50 W) U. Base thermostat—closes at 140ºF
(60ºC), opens at 104ºF (40ºC) V. Turntable motor
W. Touch panel (back and front views)X. Cavity light
Y. FC motor Z. FC thermostat—opens at 329ºF
(165ºC), closes at 257ºF (125ºC)AA. FC ring heater AB. FC thermistor AC. Humidity sensorAD. Cavity thermostat—opens at 329ºF
(165ºC), closes at -22ºF (-30ºC)AE. Door control assembly (back view)
(includes the touch panel only)AF. UIB (user interface board)AG. LCD module
Primary, Secondary, and Monitor Interlock Switch Checkout Procedure
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 (brown wires) to the normally open
terminal (brown/white wires).
- +
1. Unplug microwave oven or disconnect power.2. Disconnect the wires at the Primary Interlock Switch.3. Check from the common terminal (brown wires) to the normally closed
terminal (orange wire).
+ -
Secondary Interlock
1. Unplug microwave oven or disconnect power.2. Disconnect the wires at the Secondary Interlock Switch.3. Check from the common terminal (blue wire) to the normally open
terminal (white/blue wires).
- +
Monitor Interlock
1. Unplug microwave oven or disconnect power.2. Disconnect the wires at the Monitor Interlock Switch.3. Check from the common terminal (blue wire) to the normally closed
terminal (white/red wires).
+ -
AB
CDEFG
H
I
JK
LMNOPQR
UVW
Y
Z
AAAB
XQ
ACAD
AE
AF AG
W
ST
4
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
TROUBLESHOOTINGDo not continue with the diagnostics of appliance if the household fuse is blown, a circuit breaker is tripped or if there is less than 120-volt power supply at the wall outlet.Complete the following steps before checking microwave oven circuitry:1. Unplug microwave oven or disconnect power.2. Discharge high-voltage capacitor and disconnect white
wire from power transformer.
3. Check for loose wiring or incorrect wiring within microwave oven.
4. All testing must be done with an ohmmeter having a sensitivity of 20,000 ohms per volt DC or greater, and powered by at least a 9-volt battery.
5. All operational checks using microwave energy must be done with the microwave oven loaded with a minimum of 8 oz (250 mL) of water in a microwave safe container.
Inverter and Magnetron Circuit
Forced Convection (FC) Circuit
Hood Exhaust Fan on Low Speed
MonitorInterlockSwitch
PrimaryInterlockSwitch
SecondaryInterlockSwitch
(NC) (NO)(NO) (NC) (NO)L N
MonitorInterlockSwitch
PrimaryInterlockSwitch
SecondaryInterlockSwitch
(NC) (NO)(NO) (NC) (NO)L N
Filter2
49031
BU
CavityThermostat
PrimaryInterlockSwitch
MW Relay BUBR
P56
P66CN702
P65
CN701
CN703Inverter
Magnetron
12
3
32
1
R
R Relay Control Board
Relay Board
BR
10
SecondaryInterlockSwitch
BK BU
RibbonCable
L
BK BRN
WFilter
RibbonCable
Fuse20 Amp
WaveguideThermostat
BU
Fuse 500mA
4170Inverter
1 2
P51 P52BR G R
Relay Board
GRP53-3
BR BR
P52
WFC Ring Heater
P51
2 1FCH Relay
4905
RR R
P53 -4FCF
FCFA Relay
4907FCTH
R
BR
R GY
GY
FC Thermostat
NW
LBK BU BUFilter
Fuse20 Amp
PrimaryInterlockSwitch
WaveguideThermostat
CavityThermostat
Filter
Fuse500mA
4170Inverter
HF
MotorCapacitor
L NFuse
20 AmpBR WBK B R BR
P51B U B UG
Relay Board
P52
R
Filter Filter
CavityThermostat
R
WaveguideThermostat
R R BU BR
W W
P82-3
P82-2
P81-8
P54-1PR2 PR1Power
Resistor-2Power
Resistor-1P81-3P82-1
Relay 4930BK BK BK BR BK
P54-4R
P81-5
5
Hood Exhaust Fan on Mid-1 Speed
Hood Exhaust Fan on Mid-2 Speed
Hood Exhaust Fan on High Speed Manually
Hood Exhaust Fan on High Speed Automatically
Fuse500mA
4170
Inverter
HF
MotorCapacitor
L NFuse
20 AmpB R WBK BR BR
P51B U B UG
Relay Board
P52
R
Filter Filter
CavityThermostat
R
WaveguideThermostat
R R R BU
W W
BRP82-3
P82-2
P81-5P81-8
P54-1PR2 PR1Power
Resistor-2Power
Resistor-1P81-3P82-1
Relay 4930BK BK BK BR BK
YGY
P81-7P54-2
Relay 4932
BUOR
P54-3P81-9
P54-4
Fuse500mA
4170Inverter
HF
MotorCapacitor
L NFuse
20 AmpB R WBK B R BR P51 B U B UG
Relay Board
P52
R
Filter Filter
CavityThermostat
R
WaveguideThermostat
R R R BU
W W
BRP82-3
P82-2
P81-5P81-8
P54-1PR2 PR1Power
Resistor-2Power
Resistor-1P81-3P82-1
Relay4930
BK BK BK BR BK
YGY
P81-7P54-2
Relay4931
P54-4
Fuse500mA
4170Inverter
HF
MotorCapacitor
L NFuse
20 AmpBR WBK BR BR P51 B U B UG
Relay Board
P52
R
Filter Filter
CavityThermostat
R
WaveguideThermostat
R R R BU
W W
BRP82-3
P82-2
P81-5P81-8
P81-9P82-1
Relay 4930
BK BU OR P54-3
Relay4931
Relay4932BK
P54-4
Fuse500mA
4170Inverter
HF
MotorCapacitor
L NFuse
20 AmpBR WBK BR BR P51 B U B UG
Relay Board
P52
BK
R
BK
Filter
BaseThermostat
Filter
CavityThermostat
R
WaveguideThermostat
R R R BU
W W
BR
BKP81-4P82-1
P82-3
P82-2
P81-5P81-8
BU
P54-4
6
Cooling Fan Motor Circuit
Turntable Motor Circuit
Door Open—Oven Cavity Light Is On
Cooktop Light on Variable Light
CF
P83-2
P83-1
CF Relay4901
Relay Board
BR
BU
GBR BR P52P51
CavityThermostat
BR BU BUN
WL
BKFilterFilter
Fuse20 Amp
WaveguideThermostat
RFuse 500mA
4170Inverter
BU P54-4
P53-2
W
TT
Relay Board
BR
W
P81-5
R
GBR BRP52P51
CavityThermostat
BR BU BUN
WL
BKFilterFilter
P81-6
Fuse20 Amp
TT Relay4906
WaveguideThermostat
RFuse 500mA
4170Inverter
P53-1
P54-4
FilterL N
Fuse20 Amp BR
WBK BR BRP51 P52
Fuse 500mA
Inverter4170
4121
Fuse 500mA
P 6 11 2 3
BU B UG
Relay ControlBoard
Relay Board
P63
OR
12
Filter
PrimaryInterlock
Switch
CavityThermostat
CavityLamp
P55-1
R
WaveguideThermostat
RR
P55-2 P55-3
P62-1
L NFuse
20 Amp
BR WBK BR BR P51 P52BU BUG
Relay BoardFuse
500mAInverter
P582
1 W
W
W
T R
Y
W
T R
Y
H L H L
P84-1
P81-2
4170
Filter Filter
CavityThermostat
R
WaveguideThermostat
P81-1
P84-2
7
NOTE: After convection is on, the cooling fan and hood exhaust fan may be on for up to 10 minutes for cooling.
Touch Panel
Touch Panel and Relay Control Board Tests
To access the test mode:1. Unplug microwave oven or disconnect power.2. Open the microwave oven door.3. Press and hold STOP.
4. Plug in microwave oven or reconnect power.5. Release STOP and close microwave oven door.NOTE: When the door is closed, if the STOP key is pressed during this diagnostic routine, you will exit the test mode.
Test Mode Table
Microwave Oven Power Output Test1. Place 8 oz (250 mL) of lukewarm water in the center of the
microwave oven.2. Operate on HIGH power level for 2 minutes. Water should
be hot.
NOTE: If the water takes longer than 2 minutes to heat, this may indicate either the operating voltage is lower than 110 volts or there is a problem with the microwave oven.
Troubleshooting Circuit Test Chart
Cooking Mode Magnetron Convection Element Cooling Fan Convection Fan Hood Exhaust Fan
Microwave only On On
Convection On On On On
Microwave and Convection Combination
On* On* On On On
*Magnetron and convection elements turn on alternately, not simultaneously.
Screen Display Display Explanation
UIB SW ver Version number of UIB (user interface board) software
PB SW Ver Flash Version number of power board (relay control board) software
FC sensor (ºC) The temperature (ºC) measured by FC (forced convection) sensor—maximum 250ºC
UIB sensor (ºC) The temperature (ºC) measured by UIB (user interface board) sensor—ranges about 5ºC above room temperature, if oven has not been used recently
Magnetron sensor (ºC) The temperature (ºC) measured by magnetron sensor—maximum 125ºC
HUM PWM Humidity level inside unit—ranges between 8,000 and 9,500, depending on humidity level in oven cavity
Screen Display Display Explanation
Hood Key Hood key number
Quantum FMEA Quantum key stuck or the X, Y error
EEPROM Version number of PB (relay control board) EEPROM (Electrically Erasable Programmable Read-Only Memory)
MW reply error MW relay error
Smps FB error Smps feedback error
Hum sensor error Humidity sensor error
Cavity sensor error Cavity sensor error
Magnetron sensor error Magnetron sensor error
EEPROM error Power board (relay control board) error
8
Failure Codes IndicationsNOTE: 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 Condition Recommended Repair Procedure
F1.E1 Relay control board defective
1. Unplug microwave oven or disconnect power.2. Replace the relay control board.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.
F2.H1 Hood keys stuck 1. Unplug microwave oven or disconnect power.2. Check the communications cable from UIB to the touch panel board.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.5. If problem persists, unplug microwave oven or disconnect power.6. Replace the door control assembly. 7. Replace all parts and panels before operating.8. Plug in microwave oven or reconnect power.
F2.H2 Hood/light switch defective 1. Unplug microwave oven or disconnect power.2. Check the communications cable from UIB to the touch panel board.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.5. If problem persists, unplug microwave oven or disconnect power.6. Replace the door control assembly. 7. Replace all parts and panels before operating.8. 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. Replace all parts and panels before operating.5. 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. Replace all parts and panels before operating.5. Plug in microwave oven or reconnect power.6. If problem persists, unplug microwave oven or disconnect power.7. Replace relay control board.8. Replace all parts and panels before operating.9. Plug in microwave oven or reconnect power.
F3.T1 UIB (user interface board) thermistor
1. Unplug microwave oven or disconnect power.2. Check the connections from the UIB to the relay control board.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.5. If problem persists, unplug microwave oven or disconnect power.6. Replace relay control board.7. Replace all parts and panels before operating.8. Plug in microwave oven or reconnect power.9. If problem persists, unplug microwave oven or disconnect power.10. Replace the UIB.11. Replace all parts and panels before operating.12. Plug in microwave oven or reconnect power.
F3.T2 FC thermistor 1. Unplug microwave oven or disconnect power.2. Check FC thermistor connection.3. Replace the FC thermistor.4. Replace all parts and panels before operating.5. Plug in microwave oven or reconnect power.6. If problem persists, unplug microwave oven or disconnect power.7. Replace relay control board.8. Replace all parts and panels before operating.9. Plug in microwave oven or reconnect power.
9
F3.T4 Magnetron sensor 1. Unplug microwave oven or disconnect power.2. Check magnetron sensor connection.3. Replace the magnetron sensor.4. Replace all parts and panels before operating.5. Plug in microwave oven or reconnect power.6. If problem persists, unplug microwave oven or disconnect power.7. Replace relay control board.8. Replace all parts and panels before operating.9. Plug in microwave oven or reconnect power.
F6 MW relay 1. Unplug microwave oven or disconnect power.2. Check the cable from Relay 4903 to inverter.3. Check to see if the relay (4903 on relay control board) contact has welded
closed.4. Replace all parts and panels before operating.5. Plug in microwave oven or reconnect power.6. If problem persists, unplug microwave oven or disconnect power.7. Replace relay board.8. Replace all parts and panels before operating.9. Plug in microwave oven or reconnect power.10. If problem persists, unplug microwave oven or disconnect power.11. Replace relay control board.12. Replace all parts and panels before operating.13. Plug in microwave oven or reconnect power.
F7 Power to magnetron interrupted
1. Unplug microwave oven or disconnect power.2. After 40 seconds, check to see whether this solves the problem. 3. Unplug microwave oven or disconnect power.4. Check for reversed plug connection on controls or loose wiring.5. Check cooling fan operation.6. Check the magnetron.7. Check P65 connection on the relay control board.8. Check the P56/P66 connection between relay board and relay control board.9. Check wiring to the 1200W inverter and control system. 10. Check operation of all interlock switches. 11. Replace inverter, if defective. 12. Replace all parts and panels before operating.13. Plug in microwave oven or reconnect power.14. If problem persists, unplug microwave oven or disconnect power.15. Replace relay control board.16. Replace all parts and panels before operating.17. Plug in microwave oven or reconnect power.
F9 Relay control board communications error
1. Unplug microwave oven or disconnect power.2. Check the communications cable from P66 to P56 between relay control
board and relay board.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.5. If problem persists, unplug microwave oven or disconnect power.6. Replace the relay board and relay control board.7. Replace all parts and panels before operating.8. 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.3. Replace all parts and panels before operating.4. Plug in microwave oven or reconnect power.5. If problem persists, unplug microwave oven or disconnect power.6. Replace the door control assembly.7. Replace all parts and panels before operating.8. Plug in microwave oven or reconnect power.
Display Likely Failure Condition Recommended Repair Procedure
10
Component Tests
IMPORTANT:
■ Unplug microwave oven or disconnect power.■ Discharge the high-voltage capacitor and remove the
lead wires from the primary winding of the high-voltage transformer before conducting any of the following tests.
■ Remove the lead wires from the related component before conducting any of the following tests.
■ All operational checks using microwave energy must be done with the microwave oven loaded with a minimum of 8 oz (250 mL) of water in a microwave safe container.
■ Conduct a microwave energy test after performing any tests or repairs to the microwave oven.
■ Check that all wire leads are in the correct position before operating the microwave oven.
■ Grasp wire connectors when removing the wire leads from microwave oven parts.
■ All testing must be done with an ohmmeter having a sensitivity of 20,000 ohms per volt DC or greater, and powered by at least a 9-volt battery.
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:
■ Filament terminals: Normal: Less than 1 ohm■ Filament to chassis: Normal: Infinite
Cooling Fan Motor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 41 +/- 5 ohms■ Abnormal: Infinite
FC Motor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 21.5 +/- 5 ohms■ Abnormal: Infinite
Turntable Motor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 2.2k +/- 0.5k ohms (approximate)■ Abnormal: Infinite
Hood Exhaust Fan Motor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Pin 1 (BK) and 2 (W): Normal: 17 +/- 5 ohms; Abnormal: Infinite■ Pin 1 (BK) and 3 (R): Normal: 21 +/- 5 ohms; Abnormal: Infinite
AC Line Filter 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ P31 and P32, P33 and P34: Normal: Greater than or equal to 300k ohms; Abnormal: Less than or equal to 100k ohms
■ P31 and P34, P32 and P33: Normal: 0 ohms; Abnormal: Greater than or equal to 100k ohms
FC Ring Heater 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 9 +/- 3 ohms■ Abnormal: Infinite
1 2 3BK
W
R
P34
P31
P33
P32
11
Humidity Sensor 1. Unplug microwave oven or disconnect power.2. Remove the 3-pin connector from Relay Control Board.3. Measure resistance across pins 1 and 3, and across pins 2 and 3:
■ Normal: 2.8k ohms (approximate) at 77º +/- 10ºF (25º +/- 10ºC)■ Abnormal: Infinite
Thermostats NOTE: Refer to “Parts Layout” for opening and closing temperatures.1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure continuity:
■ FC, Cavity and Waveguide Thermostats: Normal: Continuity; Abnormal: Infinite■ Base Thermostat: Normal: Infinite; Abnormal: Continuity
FC Thermistor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 230k +/- 20% ohm at 77ºF (25ºC)■ Abnormal: Infinite
Magnetron Sensor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 10k +/- 5% ohms at 77ºF (25ºC)■ Abnormal: Infinite
Motor Capacitor 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: Momentarily 0 ohms, then goes to infinite■ Abnormal: Infinite
FC Thermoactuator 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 1.2k +/- 0.5k ohms■ Abnormal: Infinite
Cavity / Hood Lamp 1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 1.5 +/- 0.5 ohms■ Abnormal: Infinite
Relay Control Board NOTE: Do not try to repair or make adjustments to the relay control board.1. Unplug microwave oven or disconnect power.2. Check wiring to relay control board.3. Visually inspect P61, P62, P63, P64, P65, P66, P67, P68, P71, P73 and P74 to see
whether there are signs of overheating or any signs of failure due to loose wires, bad crimping, etc.
Power Resistor-1(20 ohm/ 25 W)
1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 20 +/- 2 ohm at 77ºF (25ºC)■ Abnormal: Infinite
Power Resistor-2 (41 ohm/50 W)
1. Unplug microwave oven or disconnect power.2. Remove wire leads.3. Measure resistance:
■ Normal: 41 +/- 2 ohm at 77ºF (25ºC)■ Abnormal: Infinite
Components Tests/Results
123
Y/G
BKRW
FC / Cavity /Waveguide Thermostat
BaseThermostat
31
21
1P
62
1P
61
61
52
P6
31
P6
6
P6
41
P6
8
70
01
46
25
P6
51
P6
71
P7
11
P7
31
P7
41
Checking Inverters
Measure Oven Input Current
Connect an ammeter (Valhalla Scientific 2101 or equivalent 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 1200W inverter is probably OK. Check the magnetron. See Magnetron test in “Component Tests.”
If less than 0.5A:There is no input to the 1200W inverter. Check the following:1. Unplug microwave oven or disconnect power.2. No AC voltage supply. Check relay control board and
wiring.3. No control signal. Check relay control board and wiring.
Check the 1200W Inverter
NOTE: Do not try to repair the inverter board, nor try to make any adjustments to the board.
Check wiring to 1200W inverter:1. Unplug microwave oven or disconnect power.2. Visually inspect 4 connectors on the 1200W 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.
Relay Board NOTE: Do not try to repair or make adjustments to the relay board.1. Unplug microwave oven or disconnect power.2. Check wiring to relay board.3. Visually inspect P51, P52, P53, P54, P55, P56 and P57 to see whether there are signs
of overheating or any signs of failure due to loose wires, bad crimping, etc.
Components Tests/Results
49
14
49
04
49
24
49
05
P52
P51
31
1049
06
49
01
49
07
1P53
3191
49314932
1P54
4903
4121
P54
1
P56
P57
1
4170
P581
5174
5170
15A
Ampères
A. CN702B. Heat sinkC. E701D. High-voltage output
to magnetron
E. CN703F. Control signal in/outG. CN701H. 120V AC
B
G
A
C
D
EF
H
W10220004A / 4619651997711/09
FOR SERVICE TECHNICIAN’S USE ONLY