Whirlpool WML75011HN Tech Sheet

FOR SERVICE TECHNICIAN’S USE ONLY



3

2

4


Tech Sheet

Do not discard

W11279382A


DANGER

Electrical Shock Hazard

Only authorized technicians should

perform diagnostic voltage measurements.

After performing voltage measurements,

disconnect power before servicing.

Failure to follow these instructions can

result in death or electrical shock.

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.

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

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 Operation

2.

Proper Door Closing

3.

Seal and Sealing Surfaces (Arcing, Wear and Other Damage)

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, wave guide 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 this manual before the oven is released to the

owner.

e.

A microwave leakage check to verify compliance with the Federal

Performance Standard (CSA in Canada) 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.

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

Condition

Recommended Repair Procedure

“Enter

clock”

Power failure

After a power failure, “Enter clock” will be flashing. Press CANCEL to end this indication. The colon (:) will appear when in

Standby mode.

F2E1

Touch panel

failure

1.

Unplug microwave oven or disconnect power.

2.

Replace touch panel.

3.

Replace all parts and panels before operating.

4.

Plug in microwave oven or reconnect power.

5.

If problem persists, refer to “ACU Pin Voltage

Matrix.”

F1E4

MW Relay

1.


2.

Check wiring to Relay 4903

3.

Check to see if relay (4903 on ACU) contact

has welded closed.

4.


5.


6.

If problem persists, refer to “ACU Pin Volatage

Matrix” to check P2-2 (Door), P1-3 (N), and

P1-1(L).

F4E4

Humidity

sensor error

1.

Enter the Diagnostics mode (press CANCEL - CANCEL -

START), and then press COOK to display the humidity sensor

reading. If display does not show The value between “2000 and

9000” continue to Step 2.

2.


3.

Connect a new humidity sensor ACU to cable.

4.


5.


6.

Enter the Diagnostics mode (press CANCEL -

CANCEL - START), then press COOK to see if

failure code reappears.

NOTE:

There may be a delay (approximately

1 minute, 20 seconds) before the F4E4 failure

code is displayed.

7.

If the F4E4 failure code reappears, unplug

microwave oven or disconnect power.

8.

Replace ACU.

9.


10.


F8E5

Exhaust air

template

detection

failure

1.

Enter the Diagnostics mode (press CANCEL - CANCEL -

START), and then press SETUP or CLOCK to display the

exhaust air temperature sensor reading. Verify the sensor

temperature reading is at room temperature (typically 50ºF

to 90ºF [10ºC to 32ºC]) and verify failure code. If failure code

matches complaint, continue to Step 2.

2.


3.

Disconnect sensor from ACU.

4.

Measure sensor resistance between connector pins and confirm

reading is between 9.5 k

Ω

and 10.5 k

Ω

at room temperature. If

measurement is not correct or if a short or open circuit is found,

replace sensor.

5.


6.


7.

Enter the Diagnostics mode (press CANCEL

- CANCEL - START), and then press SETUP

or CLOCK to display the cavity temperature

sensor reading. Verify the sensor temperature

reading. If it is still not correct, replace ACU.

8.

If failure does not reappear, stop.

PRIMARY, SECONDARY, MONITOR AND DOOR 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 making any continuity readings.

NOTE:

The Secondary Interlock Switch, Monitor Interlock Switch, Primary Interlock Switch and Door Interlock Switch are mounted in the door lock

switch cradle. All the Interlock Switches 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.


2.

Disconnect the wires at the Primary Interlock Switch.

3.

Check from the common terminal (black/black wires) to the normally open terminal (black/white wires).

4.

Reconnect wires to switch.

-

+

Monitor

Interlock

1.


2.

Disconnect the wires at the Monitor Interlock Switch.

3.

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

4.


+

-

Secondary

Interlock

1.


2.

Disconnect the wires at the Secondary Interlock Switch.

3.

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

4.


-

+

Door

Interlock

1.


2.

Disconnect the wires at the Door Interlock Switch.

3.

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

4.


+

-

(+) Continuity (-) No Continuity

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.


2.

Discharge the high-voltage capacitor.

3.

Disconnect the high-voltage transformer primary windings.

4.

Attach the voltmeter leads to the high-voltage transformer primary

input wires.

5.


6.

Close door and program the microwave oven to operate

for 30 seconds.

7.

Press START.

8.

Check the input voltage at the high-voltage transformer primary

input wires. If the voltage is not close to the rating voltage

120 ± 15 VAC, unplug microwave oven or disconnect power. Check

the circuitry as follows:

■

Measure resistance of the fuse, micro-switches, and thermostats.

Replace any failed components. (Refer to the wiring diagram.)

■

Check for loose terminals. (Refer to the wiring diagram.) Check

all of the terminals on the main route from the power supply to

the high-voltage transformer.

■

Check for loose or failed connectors on the PCBA (P1, P2).

If these check out OK, plug in microwave oven or reconnect

power.

■

Check for ACU failure. Refer to “ACU Pin Voltage Matrix.”

9.

If the input voltage at the high-voltage transformer primary input

wires is close to the rating voltage 120 ± 15 VAC, unplug microwave

oven or disconnect power.

10.

Check the power supply components. Refer to “Component Tests.”

■

High-voltage transformer

■

High-voltage capacitor

■

High-voltage diode

11.

If the power supply components check out OK, check the

connection between the magnetron and the high-voltage

transformer.

12.

If all of the components check out OK, replace the magnetron.

13.

Reconnect the high-voltage transformer primary windings.

ACU PIN VOLTAGE MATRIX

Check for proper voltage by completing the following steps:

1.


2.

Connect voltage measurement equipment to the terminals listed

below. (P1-3 and P2-3 are neutral.)

3.

Plug in microwave oven or reconnect power, and confirm

voltage reading.

4.


Abbreviations

HL - Hood Light

N - Neutral

CL - Cavity Light

HF - Hood Fan

L - Line Voltage

TT - Turntable Motor

NFS - Neutral for Switch

NOTE:

When checking voltage readings on ACU, connect the Negative test lead of voltmeter to connector P1-3. Use the positive test lead

to probe connectors designated below.

MW Oven Plugged In—Sitting Idle—ACV Readings

MW Oven

Running—

ACV

Readings

Pin Name

Wire Color

Power

On, Door

Closed

Power On,

Door Open

Hood

Fan

Motor—

High

Hood Fan

Motor—

Med-

High

Hood

Fan

Motor—

Medium

Hood

Fan

Motor—

Low

Hood

Light—

High

Hood

Light—

Low

Microwave

Oven Start

P1-1 (L)

BLACK

120

120

120

N/A

120

120

120

120

120

P1-3 (N)

BLUE

0

0

0

N/A

0

0

0

0

0

P2-1 (NFS)

BLUE AND GREEN

0

0

0

N/A

0

0

0

0

0

P2-2 (Door)

ORANGE

0

120

0

N/A

0

0

0

0

38

P2-3 (N)

WHITE AND BLACK

0

120

0

N/A

0

0

0

0

0

P4-1 (CL/CF)

BLACK

0

120

0

N/A

0

0

0

0

120

P4-2 (TTM)

RED

0

0

0

N/A

0

0

0

0

120

P4-4 (ODM)

BLACK

0

0

0

N/A

0

0

0

0

0

P14-1 (L)

BLACK

120

120

120

N/A

120

120

120

120

120

P14-3 (HF-H)

BLACK

18

20

120

N/A

19

19

19

18

20

P14-4 (HF-L)

WHITE

18

22

20

N/A

19

120

20

19

22

P14-5 (HF-M)

GREY

18

25

19

N/A

120

20

19

18

23

P14-6 (HF-ML)

BLACK

20

23

21

N/A

68

21

21

20

24

N

(NO)

(NC)

Monitor

Interlock

Switch

Primary

Interlock

Switch

(NC)

(NO)

Secondary

Interlock

Switch

(NC)

(NO)

P 2-3

P 2-1

L

(NO)

(NC)

P 2-2

Door

Interlock

Switch

N

(NO)

(NC)

Monitor

Interlock

Switch

Primary

Interlock

Switch

(NC)

(NO)

Secondary

Interlock

Switch

(NC)

(NO)

P 2-3

P 2-1

L

(NO)

(NC)

P 2-2

Door

Interlock

Switch

Door Closed

Door Open

NOTES:

■

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).

■

Interlock and Monitor switches cannot be adjusted and all these switches should be replaced if any one of them is found to be defective. After

replacing interlock/monitor switches, reconnect wires to switch and check for continuity. Safety interlocks and monitor switches will actuate

within 2 mm.

NOTE:

For 50 V and over, the tolerance is ± 15 V. For 0 V, the tolerance is ± 3 V.

NOTE:

There is a empty terminal on P1 and P4 connector.

TOUCH PANEL

Touch Panel and ACU Test

The microwave hood combination is provided with a self-diagnostic routine that can be accessed through the touch keypad.

To initiate this routine:

1.

Plug in microwave oven or reconnect power, In idle mode, close the

door, turn off hood light and hood fan.

2.

Open and close door, then press CANCEL - CANCEL - START

within 3 seconds.

All LED/LCD segments will be lit to indicate the Test mode has been

entered.

3.

Open door. The model number will be displayed.

4.

Close door. All display segments will be lit.

5.

Press indicated keypad for correct display readout and beep.

NOTE:

If the Cancel button is pressed during this diagnostic routine,

you will exit the Test mode.

2

1

2

1

4

3

6

5

8

7

P9

3

2

1

P8

3

2

1

4

3

2

1

P10

1

2

3

P2

NFS

DOOR

N

2

1

MW-4903

ACU

1

2

.

4

P4

1

.

3

N

P1

L

P5

2

1

P6

3

4

3

2

1

P7

4

3

2

1

P7-1

2

1

2

1

2

1

FC/CL-4904

GRILL ST/HL_LO-490

6

GRILL/HL_HI-4905

CONNECTORS ON PCBA

CONNECTORS ON HOOD CONTROL BOARD

P15

1

1

2

3

3

4

4

5

5

6

6

7

7

8

P14

NOTE:

There is a empty terminal on P14

Whirlpool WML75011HN Tech Sheet

Whirlpool WML75011HN Manual

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