Maytag Services ACE5302 User manual

International Commercial Microwave—Technical Information
March 2005 1 16025975
©2005 Maytag Services
230 V, 50 Hz Models
ACE5302 P1331307M UACE5302 P1331308M
DS30E2 P1331309M UDS30E2 P1331310M
UCA2000NT2 P1331311M
•Due to possibility of personal injury or property damage, always contact an authorized technician for servicing or
repair of this unit.
•Refer to Service Manual RS5320016 for installation, operating, testing, troubleshooting, and disassembly
instruction.
All safety information must be followed as provided in Service Manual RS5320016.
!
WARNING
To avoid the risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
Models ACE5302
DS30E2
UACE5302
UDS30E2
UCA2000NT2
Power Source
Voltage AC 230 VAC 230 VAC
Amperage (Single Unit) 16 A 13 A
Frequency 50 Hz 50 Hz
Single Phase, 3 wire grounded X X
Plug CEE 7/7 Schuko BS1363A
Power Output −Microwave
Nominal microwave energy (IEC705) 1000 Watts 1000 Watts
Traditional test method 900 Watts 900 Watts
Minimum temperature rise ( ∆ T) 18ºF / 10ºC 18ºF / 10ºC
Operating Frequency 2450 MHz 2450 MHz
Power Consumption
Microwave only 1800 Watts 1800 Watts
Convection only 2700 Watts 2200 Watts
Combination 3400 Watts 3000 Watts
Dimensions
Cabinet (in / cm)
Width 49 cm (19 1/4") 49 cm (19 1/4")
Height 46 cm (18 1/4") 46 cm (18 1/4")
Depth 67 cm (26 1/4") 67 cm (26 1/4")
Oven Interior (in / cm)
Width 33 cm (13") 33 cm (13")
Height 27 cm (10 1/2") 27 cm (10 1/2")
Depth 38 cm (15") 38 cm (15")
Weight
Crated 46 kg. (102 lbs.) 46 kg. (102 lbs.)
Uncrated 43 kg. (95 lbs.) 43 kg. (95 lbs.)

Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
2
Illustration Component Test Results
Thermal cutout Disconnect all wires from TCO.
Measure resistance across terminals.
Control TCO..........................................
Fan TCO...............................................
Magnetron TCO ....................................
Heater Box Limiter ................................
Open at 300°F (149°C) and
closed at 257°F (125°C)
Open at 125°F (52°C) and
closed at 160°F (71°C )
Open at 235°F (113°C) and
closed at 150°F (66°C)
Open at 351°F (177°C) and
closed at or below 18°F (-8°C)
Diode Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Infinite resistance should be measured
in one direction and 50KΩor more in
the opposite direction.
NOTE: Ohmmeter must contain a
battery of 6 volts minimum.
MT2
MT1 GATE
Triac Disconnect wires to triac.
Measure resistance from:
MT1 to MT2 ..........................................
MT1 to Gate..........................................
MT2 to Gate..........................................
All terminals to ground ..........................
Caution - Do not operate oven with
wire to terminal MT2 removed.
Infinite
Approximately 15 Ω, then reverse
meter leads 30 Ω
Infinite
Infinite
Triac 1 (top) is for front element
Triac 2 (middle) is for rear element
Triac 3 (bottom) is for microwave
Measure voltage from:
MT1 to Gate
0.8 VAC when energized. If no
voltage, check H.V. board and wiring.
Capacitor Discharge Capacitor
Remove wires from capacitor terminals and
connect ohmmeter, set on highest
resistance scale to terminals.
Also check between each terminal and
capacitor case.
Between Terminals: Meter should
momentarily deflect towards zero then
return to over 5 MΩ. If no deflection
occurs, or if continuous deflection
occurs, replace capacitor.
Terminal to Case: Infinite resistance
Snubber assembly Disconnect wires to snubber.
Measure resistance across terminals.
Infinite
Magnetron Discharge Capacitor
Remove wires from magnetron and connect
ohmmeter to terminals. Also check
between each terminal and ground.
Between Terminals: Less than 1 Ω
Each terminal to ground measures
Infinite resistance.
Note: This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
Microwave blower
motor
Remove all wires from motor.
Measure resistance across coil.
Approximately 30 Ω

Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
3
Illustration Component Test Results
4
COM
230
220
5
6
Transformer Discharge Capacitor
Remove all wires from terminals.
Measure resistance from:
230 to COM
208 to COM
230 to Ground
208 to Ground
Terminal 5 to 6
Terminal 4 to Ground
< 1.5 Ω
< 1.5 Ω
Infinite
Infinite
< 1 Ω
Approximately 70 Ω
7
8
2
4
3
5
Interlock switch
Door Closed
2
4
7
3
5
8
Primary
Secondary
Monitor
Disconnect wires to switch.
With door open measure resistance from:
Terminal 2 to 3
Terminal 4 to 5
Terminal 7 to 8
With door closed measure resistance from:
Terminal 2 to 3
Terminal 4 to 5
Terminal 7 to 8
Infinite
Infinite
Indicates continuity
Indicates continuity
Indicates continuity
Infinite
A
B
Convection blower
motor
Remove wires from motor.
Measure resistance across
terminals A and B.
Approximately 20 Ω
Heating element
assembly
Disconnect wires from terminals.
Measure resistance across heating
element.
Front element 1200 W ......................
Rear element 1500 W ......................
Front element 1100 W ......................
Rear element 1100 W ......................
Indicates continuity
44 Ω
35 Ω
48 Ω
48 Ω
Resistance thermal
device (RTD)
Temperature
0°C (32°F)...................................................
177°C (350°F) .............................................
Resistance
1000 Ω
1654 Ω
Lamp receptacle Test continuity of receptacle terminals. Indicates continuity with bulb
screwed in.
IN OUT
Blue
Brown Brown
Blue
Line filter
Disconnect wire from terminals.
Measure resistance of the following
terminals:
Blue to Blue............................................
Brown to Brown......................................
< 1 Ω
< 1 Ω

Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
4
Illustration Component Test Results
Side touch panel Continuity is indicated as 100 Ωand
below.
1
Pad
1
2
3
4
5
6
7
8
9
0
Start
Stop/Reset
Trace
3 & 5
3 & 6
3 & 7
3 & 8
3 & 9
4 & 5
4 & 6
4 & 7
4 & 8
4 & 9
5 & 6
6 & 9
Measurement
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Top touch panel Continuity is indicated as 100 Ωand
below.
1
Pad
Preheat
Time Entry
Temp Entry
Power Level
Stage
Program Save
Hidden Pad
Trace
3 & 4
5 & 7
7 & 8
5 & 8
5 & 9
6 & 7
8 & 9
Measurement
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Continuity
Wire harness High voltage board
to display module
harness
Test continuity of wires. Indicates continuity
Display board
J1
J5
J6 J4
Pin 1
Pin 1
Pin 1
Pin 1
Side
Touch
Panel
Connector
H.V. board
Connector
Interlock
Connector
Top
Touch
Panel
Connector
3.5 VAC should be indicated whenever the oven is plugged into a power supply.
If voltage is present and no display is indicated, replace display board.
If no voltage is present, check wire harness connections and H.V. board.

Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
5
H.V. board
Pin 1
E1
E2
E3
J5
J1
J2
E4
E5
J3
J4 E7
E6 J7
J6
J8
Pin 28
Pin 1
Pin 1
Pin 1
Pin 1
Pin 1
Pin 1
Pin 1
Pin 50
Clip Clip Clip
Clip Clip Clip Clip
In straight convection mode, both elements operate simultaneously.
In combination mode, the rear element will operate simultaneously with either the microwave or front element.
Function Test Set-Up Meter
Setting
Probe Placement Results
Input to H.V. board At H.V. board Volts J1 pin 1 (Black wire)
& J1 pin 2 (Red wire)
Line voltage
Output to display
board
Disconnect
J5 connector
Volts J5 pin 28 &
J5 pin 50
- 24 VDC
Relay Function Test Set-Up Meter
Setting
Probe Placement Results
K1 Cooling fan Disconnect
J2 connector
Ohms J1 pin 1 (Black wire)
& J2 pin 4
Test mode 5 off – no continuity
Test mode 5 on – < 1 Ω
K2 Convection
motor
Disconnect
J2 connector
Ohms J1 pin 1 (Black wire)
& J2 pin 3
Test mode 4 off – no continuity
Test mode 4 on – < 1 Ω
K3 Cavity light Disconnect
J2 connector
Ohms J2 pin 1 &
J2 pin 2
Test mode 6 off – no continuity
Test mode 6 on – < 1 Ω
K4 Heater A
(front)
Disconnect
J3 connector
Ohms E4 & J3 pin 3 Test mode 2 off – no continuity
Test mode 2 on – < 1 Ω
K7 Microwave Disconnect
J4 connector
Ohms J4 pin 4 &
J4 pin 5
Test mode 3 off – no continuity
Test mode 3 on – < 1 Ω
K9 Heater B
(rear)
Disconnect
J4 connector
Ohms E6 & J4 pin 1 Test mode 1 off – no continuity
Test mode 1 on – < 1 Ω

Component Testing Procedures
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
6
Power Test
All Amana and Menumaster microwave oven power outputs are rated using the IEC705 standards. Using the IEC705
test method requires precision measurements and equipment that is not practical to be performed in the field. Using
the test shown below will indicate if the oven performance is satisfactory.
Test equipment required:
•1000 ml test container and thermometer (Amana power test kit R0157397 Fahrenheit / Menumaster power
test kit M95D5 Celsius).
•Digital watch / watch with a second hand for use on ovens with electromechanical timers.
Important Notes:
•Low line voltage will cause low temperature rise / power output.
•Ovens must be on a dedicated circuit, properly grounded, and polarized. Other equipment on the same
circuit may cause a low temperature rise / power output.
•This test and results are not a true IEC705 test procedure and are only intended to provide servicers with an
easy means of determining if the microwave oven cooking output is correct.
Procedure
1. Fill the test container to the 1000 ml line with cool tap water.
NOTE: Water temperature should be approximately 60°F / 16°C
2. Using the thermometer, stir water for five to ten seconds; measure, and record the temperature (T1).
3. Place test container of water in the center of oven cavity and close door.
4. Heat the water for a 33-second full power cycle.
NOTE: Use a digital watch or a watch with a second hand for ovens with electromechanical timers.
1. At end of the cycle, remove test container. Using the thermometer, stir water for five to ten seconds and record
temperature (T2).
2. Subtract the starting water temperature (T1), from the ending water temperature (T2) to obtain the temperature
rise (
∆ T).
3. If the temperature rise (
∆ T) meets or exceeds the minimum, the test is complete. If the temperature rise ( ∆ T)
fails to meet the minimum temperature rise, test the line voltage to verify it is correct. Then repeat steps 1-6
making sure to change the water. If the temperature rise (
∆ T) fails to meet the minimum temperature rise again
the oven will require service.
Minimum Temperature Rise at Thirty -Three (33) Seconds Run Time
∆ T Cooking ∆ T Cooking ∆ T Cooking ∆ T Cooking
(°F) Power Output (°F) Power Output (°C) Power Output (°C) Power Output
10 ................. 1000 20................. 2000 5 .............. 1000 11............ 2000
11 ................. 1100 21................. 2100 5.5 ............ 1100 11.5......... 2100
12 ................. 1200 22................. 2200 6.5 ............ 1200 12............ 2200
14 ................. 1400 24................. 2400 7.5 ............ 1400 13............ 2400
17 ................. 1700 25................. 2500 9.5 ............ 1700 13.5......... 2500
18 ................. 1800 27................. 2700 10 ............. 1800 15............ 2700
19 ................. 1900 30................. 3000 10.5 .......... 1900 16.5......... 3000

Service Test
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
7
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
LMT
LMT
LMT
1
2
3
4
1 3 5 7 9
To Enter Service Mode, oven door must be closed.
Press Hidden Pad
NOTE: Unit must be in STANDBY mode.
Press Display
Toggles
Element B (Rear)
ON/OFF.
Toggles
Element A (Front)
ON/OFF.
Toggles
Microwave
ON/OFF.
Toggles
Convection
Fan ON/OFF.
Displays actual Amperage
Timer counts up to 99 seconds.
Timer counts up to 99 seconds.
Timer counts up to 62 seconds and unit shuts off.
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
Component Evaluation
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
0 = Deactivated
1 = Activated
Displays actual Amperage
Displays actual Amperage
Indicates
Service
Mode
If no Amperage, check:
Heating element
Triac 2 (middle)
H.V. board (relay K9 and
triac 2 drive voltage)
Wiring
If no Amperage, check:
Heating element
Triac 1 (top)
H.V. board (relay K4 and
triac 1 drive voltage)
Wiring
If no Amperage, check for line
voltage at H.V. transformer
primary winding.
If no voltage, check:
Interlock switch (secondary)
Magnetron TCO
Triac 3 (bottom)
H.V. board (relay K7 and
triac 3 drive voltage)
Wiring
If voltage is present, check
H.V. components and wiring.
Then
If no fan operation, check:
Convection fan motor and wheel
H.V. board (relay K2 )
Wiring
PREHEAT
ON / OFF
Hidden
Pad
NOTE: Pads will not beep when pressed.

Service Test
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
8
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
LMT
LMT
LMT
6
7
8
9
0
Toggles Oven
Light ON/OFF.
Displays # of
Magnetron Hours.
Displays # of Door Cycles
with a 1 to 1 ratio rounded
to the nearest ten
Clears Hours and Cycles
(press START to activate)
(Resets to 0).
Displays current
Temperature OFFSET.
TEMP
Display current oven
Temperature as
sensed by RTD.
Press Display Component Evaluation
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
5
Toggles Cooling
Fan ON/OFF.
If no fan operation, check:
Cooling fan motor and wheel
H.V. board (relay K1)
Wiring
If no light operation, check:
Oven light
H.V. board (relay K3)
Wiring
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT

Test Modes
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
9
Convection Temperature Test
NOTE: It is absolutely necessary to own and use a
thermocouple type oven tester to accurately
measure oven temperature. No other type of
thermometer can take its place.
NOTE: Before testing an oven to check calibration,
inspect the RTD for proper mounting.
1. Place one wire rack in center position. Remove
any other racks and utensils.
2. Clip thermocouple to the center rack and run lead
outside oven door, or wrap thermocouple around
rack and have tip of thermocouple extend upward
towards top of cavity approximately 1".
3. Press
PREHEAT ON/OFF pad.
4. Press
PROGRAM SAVE pad.
5. Press
TEMP pad.
6. Enter 230°C (450°F).
7. Allow oven to cycle one time.
8. Record high and low peaks from next two cycles.
NOTE: Display does not indicate if heating elements
are on or off.
Fahrenheit Example:
LOW HIGH
Cycle 1 440°F 460°F
Cycle 2 439°F 461°F
879°F + 921°F = 1800°F
1800°F / 4 = 450°F average temperature
Celsius Example:
LOW HIGH
Cycle 1 230°C 240°C
Cycle 2 230°C 240°C
450°C + 480°C = 930°C
930°C / 4 = 230°C average temperature
If the average temperature is too high or too low the
oven temperature offset needs to be calibrated.
Convection Temperature Calibration
NOTE: It is normal for the average oven temperature
to vary from the oven setting by as much as
25°F (14°C). Difference will not effect cooking
since recipes are written with this difference in
mind.
Calibration
NOTE: Door must be closed.
1. Press
HIDDEN PAD .
2. Press pads
1,3,5,7, 9.
3. Press
"0" pad.
STG
COOK
PREHEAT STANDBY
ITEM POWER
CM
1
2
3
4
QTY
LEVEL
NOT READY
LMT
NOTE: Display will show the current offset setting.
4. Press the
"0" pad to change the offset.
Fahrenheit
NOTE: Offset temperature range is +40°F to -40°F
and advances in 2 and 3° increments.
Celsius
NOTE: Offset temperature range is +22°C to -22°C
and advances in 1 and 2° increments.
5. Press
STOP/RESET pad to save offset changes.
NOTE: Retest the oven after any offset changes are
made.
Fahrenheit Example:
• Oven temperature is set for 450°F
• Average of temperature test is 475°F
• Offset setting must be reduced by 25°F
• If offset is shown as 10°, press the "0" pad until -15
is shown in the display (10 – 25 = –15)
Celsius Example:
• Oven temperature is set for 230°C
• Average of temperature test is 240°C
• Offset setting must be reduced by 10°C
• If offset is shown as 5°, press the "0" pad until -5 is
shown in the display (5– 10= –5)

Display Diagnostics
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
10
CAUTION
!
All repairs as described in this troubleshooting section are to be performed only after the caution procedures one through
eight listed below have been followed.
1. Check grounding before checking for possible causes.
2. Be careful of the high voltage circuit.
3. Discharge high voltage capacitor.
4. When checking the continuity of the switches or the high voltage transformer, disconnect one lead wire from these parts
and then check continuity with the AC plug removed. To do otherwise may result in a false reading or damage to your
meter.
5. Do not touch any parts of the circuitry on the P.C. Board circuit since static electric discharge may damage this control
panel. Always touch yourself to ground while working on this panel to discharge any static charge in your body.
6. 208/230 VAC is present in the high voltage circuit board, power relay and primary circuit of low voltage transformer.
7. When troubleshooting, be cautious of possible electrical hazard.
8. When testing convection operation, convection fan may start at any time or if oven is hot.
Error Codes
During operation, the display may show the following service codes:
NOTE: Before scheduling service for any error codes, instruct customer to unplug oven for 1 minute, reconnect
power, and retest. If unit operates properly, no service call is required.
Display Description Corrective Action
Err1 Failed H.V. Board See note above.
Replace H.V. board.
Err2 Failed Touch Panel
Failed H.V. Board
Replace Touch panel.
See note above.
Replace H.V. board.
May be a failed Touch Panel. Verify before replacing H.V. Board.
Err3 Failed H.V. Board
Failed Touch Panel
See note above.
Replace H.V. board.
Replace Touch panel.
May be a failed Touch Panel. Verify before replacing.
Err4 Failed H.V. Board See note above.
Replace H.V. board.
Err5 Failed Touch Panel See note above.
If Touch Panel is pressed for more than 30 seconds, this error code will
appear.
Replace touch panel.
Err6 Failed H.V. Board See note above.
Replace H.V. board.
Err7 Error with RTD circuit
If power level shows
0-Uncalibrated.................................................
1-Shorted RTD circuit......................................
2-Open RTD circuit..........................................
See note above.
Replace H.V. board.
Check RTD and wiring to H.V. board.
Check RTD and wiring to H.V. board.
HOT See note above.
Open TCO.
Convection motor inoperative.
Restricted air filter.
H.V. board inoperative.
Broken or loose wire.
Door Door Interlock Primary Switch See note above.
Verify latch mechanism moves freely on door.
Verify J1 connector on display board is properly seated.
Test interlock switch assembly and perform door adjustment if necessary.
Replace interlock switch assembly if failed.

Wiring Diagram and Schematic
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
11
12747601
UACE5302 UDS30E2 UCA2000NT2

Wiring Diagram and Schematic
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
12
12747601
DANGER
!
HIGH VOLTAGE
UACE5302 UDS30E2 UCA2000NT2

Wiring Diagram and Schematic
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
March 2005 16025975
©2005 Maytag Services
13
12747701
ACE5302 DS30E2

Wiring Diagram and Schematic
!
WARNING
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
16025975 March 2005
©2005 Maytag Services
14
12747701
DANGER
!
HIGH VOLTAGE
ACE5302 DS30E2