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R1900M

9 – 5

NOTE: When the relay unit is replaced, set the standard voltage refer-

ring to Special Function pages.

1. CARRY OUT 3D CHECKS.

2. Disconnect all wire leads from the all switches.

3. Remove two (2) screws holding latch hook to oven flange.

4. Remove latch hook assembly from oven flange.

5. Remove the switch(es) in accordance with following procedure.

DOOR SENSING SWITCH

Push the two (2) tabs outward and pull switch forwards to release
switch.

MONITOR SWITCHES OR SECONDARY INTERLOCK SWITCHES

Remove one (1) screw and nut holding two switches together to latch
hook.

6. Now, switch(es) is now free.

1. Re-install the switch(es) in accordance with following procedure.

DOOR SENSING SWITCH

Mount the door sensing switch in the lower position of latch hook.

MONITOR SWITCHES

1) Mount the two (2) switches side by side in the top position of the

latch hook.

2) Fasten both switches together to latch hook with one (1) screw and

nut.

SECONDARY INTERLOCK SWITCHES

1) Mount the two (2) switches side by side in the middle position of the

latch hook.

2) Fasten both switches together to latch hook with one (1) screw and

nut.

2. Re-install latch hook assembly and fasten it to oven flange with two

(2) screws.

3. Re-connect all wire leads to all switches, referring to pictorial dia-

gram. Be careful to ensure proper connection of the wire leads.

4. Make sure that the monitor switches (1), (2) and all other switches

are operating properly. And check continuity of the monitor circuit.
Refer to chapter “Test Procedure” and Adjustment procedure.

1. CARRY OUT 3D CHECKS.

If the door sensing switch, secondary interlock switches (1), (2) and
monitor switches (1), (2) do not operate properly due to a misadjust-
ment, the following adjustment should be made.

2. Loosen the two (2) screws holding latch hook to the oven cavity

front flange.

3. With door closed, adjust latch hook by moving it back and forth,

and up and down. In and out play of the door allowed by the upper
and lower position of the latch hook should be less than 0.5mm.
The vertical position of the latch hook should be adjusted so that
the door sensing switch and secondary interlock switches (1), (2)
are activated with the door closed. The horizontal position of the
latch hook should be adjusted so that the monitor switches (1), (2)
are activated with the door closed.

4. Secure the screws with washers firmly.

5. Check the operation of all switches. If all switches have not acti-

vated with the door closed, loosen two (2) screws and adjust the
latch hook position.

1. In and out play of door remains less than 0.5mm when in the

latched position.

2. The door sensing switch and secondary interlock switches (1), (2)

interrupt the circuit before the door can be opened.

3. Monitor switches (1), (2) contacts close when door is opened.

4. Re-install outer case and check for microwave leakage around

door with an approved microwave survey meter. (Refer to Micro-
wave Measurement Procedure.)

Figure C-4. Latch Switch Adjustments

1. CARRY OUT 3D CHECKS.

2. Disconnect the harness of the door assembly from the control unit.

3. Remove the two (2) screws holding each of the upper and lower

hinges to the oven cavity.

4. Remove door assembly with upper and lower hinges by pulling it

forward.

Latch hook

Monitor switch (2)

Secondary
interlock switch (2)

Secondary
interlock switch (1)

Door sensing switch

Monitor switch (1)

Switch lever A

Switch lever B

Switch lever C

Latch
head

Latch
head

Handle
lever

Latch
lever

R1900M

9 – 6

5. Release upper and lower hinges and the hinge cover from door

assembly.

6. Now, door assembly is free.

NOTE: When individual parts are replaced, refer to “Door Disassem-

bly”.

1. Install the hinge cover to the upper hinge. At this time, the harness

of the door assembly should be passed through under the hinge
cover.

2. Insert the upper and lower hinges into door hinge pins.

3. Insert the upper and lower hinges with door assembly into rectan-

gular holes of oven cavity front plate.

4. Make sure that the door is parallel with oven face lines (left and

upper side line) and door latch heads pass through the latch holes
correctly.

5. Fasten upper and lower hinges firmly to oven cavity with two (2)

screws on each hinge.

NOTE: After any service to the door;

1) Make sure that door sensing switch, secondary interlock

switches (1), (2) and monitor switches (1), (2) are operating
properly. (Refer to chapter “Test Procedures”.).

2) An approved microwave survey meter should be used to

assure compliance with proper microwave radiation emis-
sion limitation standards.

Door adjustment is performed with the door properly installed and
closed and while the oven hinges are loose.

1. Loosen upper and lower hinges with phillips head screw driver.

2. Adjust the door by moving it vertically so that the top of the door is

parallel to the bottom of the control panel assembly.

3. Tighten the upper and lower oven hinge screws.

1. Door latch heads smoothly catch the latch hook through the latch

holes, and the latch head goes through the center of the latch hole.

2. Deviation of the door alignment from horizontal line of cavity face

plate is to be less than 1.0mm.

3. The door is positioned with its face depressed toward the cavity

face plate.

4. Re-install outer case and check for microwave leakage around

door with an approved microwave survey meter. (Refer to Micro-
wave Measurement Procedure.)

NOTE: The door on a microwave oven is designed to act as an elec-

tronic seal preventing the leakage of microwave energy from
oven cavity during cook cycle. 

This function does not require that door be air-tight, moisture
(condensation)-tight or light-tight. Therefore, occasional
appearance of moisture, light or sensing of gentle warm air
movement around oven door is not abnormal and do not of
themselves, indicate a leakage of microwave energy from
oven cavity. If such were the case, your oven could not be
equipped with a vent, the very purpose of which is to exhaust
the vapor-laden air from the oven cavity.

Figure C-5. Door Replacement

1. Remove the door assembly from oven cavity, referring to “DOOR

REMOVAL”.

2. Insert a putty knife (thickness of about 0.5mm) at the three (3) posi-

tions in gap between the choke cover and the door panel of the
latch heads side as shown in the fig.C-6, to free engaging parts. 

3. Push the each four (4) positions of the upper side and lower side of

chock cover by your finger as shown in the Fig.C-6, to free engag-
ing parts.

4. Pull the chock cover rightward as shown in the fig.C-6, to free

engaging parts.

NOTE: As the choke cover and door panel are engage at 14 places,

do not force any particular part.

5. Remove the choke cover carefully. (If choke cover is broken,

replace with a new one.)

NOTE: When carrying out any repair to the door, do not bend or warp

the slit choke (tabs on the door panel assembly) to prevent
microwave leakage.

Figure C-6. Choke cover

After removing choke cover; 

1. Remove the six (6) screws holding the door panel to the door

frame.

2. Release the harness from the hole of the door panel.

3. Remove the door panel from the door frame by releasing the six (6)

tabs of the door frame.

Screws

Outer case cabinet

Screws

Lower hinge

Upper hinge

Hinge
cover

Latch heads

Harness

Door handle

Choke cover

Putty knife

Door panel

Latch heads

Push

Push

Push

Push

Push

Push

Push

Push

R1900M

9 – 7

1. Remove the five (5) screws holding the key fixing plate to the door

frame.

2. Remove the key fixing plate from the door frame.

3. Remove the board cover from the key fixing plate.

4. Disconnect the flat ribbon cable of the key unit from the connector

of the switch unit.

5. Remove the connectors installed at the edge of the key unit ribbon

cable.

6. Tear the key unit from the key fixing plate.

7. Now, the key unit is free.

NOTE: 1) Before attaching a new key unit, remove remaining adhe-

sive on the key fixing plate surfaces completely with a soft
cloth soaked in alcohol.

2) When attaching the key unit to the key fixing plate, adjust

the upper edge and left edge of the key unit to the correct
position of key fixing plate.

3) Stick the key unit firmly to the key fixing plate by rubbing

with soft cloth to prevent scratching.

1. Remove the five (5) screws holding the key fixing plate to the door

frame.

2. Remove the key fixing plate from the door frame.

3. Remove the board cover from the key fixing plate.

4. Disconnect the flat ribbon cable of the key unit from the connector

of the switch unit.

5. Disconnect the harness from the connector of the switch unit.

6. Remove the one (1) screw holding the switch unit to the key fixing

plate.

7. Now, the switch unit is free.

1. Remove the one (1) screw holding the glass stopper to the door

frame.

2. Slide the front door glass leftward (latch heads side) and then slide

it upward.

3. Release the upper edge of the front door glass from the tabs of the

door frame.

4. Now, the front door glass is free.

1. Remove the latch spring from the latch angle assembly and the

latch lever.

2. Remove the one (1) screw holding the latch angle assembly to the

door frame.

3. Remove the four (4) screws holding the latch angle assembly to the

door handle.

4. Now, the door handle is free.

5. Remove the door lever from the latch heads.

6. Remove the door lever from the handle cover by releasing the tabs.

7. Now, the door lever and the handle cover are free.

1. Remove the latch spring from the latch angle assembly and the

latch lever.

2. Remove the one (1) screw holding the latch angle assembly to the

door frame.

3. Remove the four (4) screws holding the latch angle assembly to the

door handle.

4. Now, the door handle is free.

5. Remove the door lever from the latch heads.

6. Remove the two (2) latch heads and the latch lever from the latch

angle assembly together.

7. Remove the latch heads from the latch lever.

8. Now, the latch heads are free.

1. Remove the five (5) screws holding the key fixing plate to the door

frame.

2. Remove the key fixing plate from the door frame.

3. Remove the front door glass from the door frame, referring to

“FRONT DOOR GLASS REMOVAL”.

4. Remove the door handle, the door lever with the handle cover from

the door frame, referring to “DOOR HANDLE, DOOR LEVER AND
HANDLE COVER REMOVAL”.

5. Remove the one (1) screw holding the latch angle assembly to the

door frame.

6. Remove the latch angle assembly with the door latches from the

door frame.

7. Bend up all nails of the door case.

8. Remove door case from the door frame.

9. Now, the door case is free

Before the door panel is reinstalled, make sure that the pipe should be
positioned at the correct place. And the harness should pass through
the holder of the door frame and the pipe, as shown in Fig.C-7.

Figure C-7. Inside of door

Pipe

Harness

Holder

Door frame

R1900M

9 – 8

1. CARRY OUT 3D CHECKS.

2. Remove the oven lamp.

3. By pushing the tab, remove the lamp spacer with the lamp socket

from the lamp angle assembly.

4. Remove the lamp spacer from the lamp socket.

5. Pull the wire leads from the oven lamp socket by pushing the termi-

nal hole of the oven lamp socket with the small flat type screw
driver.

6. Now, the oven lamp socket is free.

Figure C-8. Oven lamp socket

Oven lamp

socket

Terminal

Wire lead

Terminal hole

Flat type small

screw driver