R-21ATP - Sharp Home Appliance Service Manual (repair manual). Page 25

23

1. CARRY OUT 3D CHECKS.
2. Remove the control panel assembly referring to "CON-

TROL PANEL ASSEMBLY REMOVAL".

3. Disconnect the leads from all switches.
4. Remove the two (2) screws holding the latch hook to

the oven cavity.

5. Remove the latch hook.
6. Push the retaining tab outward slightly and remove the

switch.

Re-install
1. Re-install each switch in its place. The 2nd. interlock

relay control switch and the latch switch are in the lower
position and the 1st. interlock switch is in the upper
position. The monitor switch is in the middle position.

2. Re-connect wire leads to each switch.

Refer to pictorial diagram.

3. Secure latch hook (with two (2) mounting screws) to

oven flange.

Power Supply Cord

Chassis 
Support

WHT

RED

L

N

Screw

Green/Yelow
Wire

Noise Filter

Bule Wire

Oven Cavity
Back Plate

Brown Wire

Power
Supply Cord

Moulding
Cord Stopper

Oven Cavity
Rear Plate

Square Hole

4. Make sure that the monitor switch is operating properly

and check continuity of the monitor circuit.    Refer to
chapter "Test Procedure" and Adjustment procedure.

Latch Hook

Tabs

Tab

Tab

Tab

Tab

Monitor Switch

Latch Switch
(Cabinet side)

1st. Interlock Switch

2nd. Interlock Relay 
Control Switch (Oven side)

If the 1st. interlock switch, latch switch, 2nd. interlock relay
control switch and monitor switch do not operate properly
due to a mis-adjustment, the following adjustment should
be made.
1. CARRY OUT 3D CHECKS.
2. Loosen the two (2) screws holding the 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 1st.
interlock switch, latch switch and 2nd. interlock relay
control switch  are activated with the door closed. The
horizontal position of the latch hook should be adjusted
so that the plunger of the monitor switch is pressed with
the door closed.

4. Secure the screws with washers firmly.
5. Check the operation of all switches. If each switch has

not activated with the door closed, loosen screw and
adjust the latch hook position.

After adjustment, check the following.
1. In and out play of door remains less than 0.5mm when

in the latched position. First check upper position of
latch hook, pushing and pulling upper portion of door

toward the oven face. Then check lower portion of the
latch hook, pushing and pulling lower portion of the
door toward the oven face. Both results (play in the
door) should be less than 0.5mm.

2. The 1st. interlock switch, latch switch and 2nd. inter-

lock relay control switch interrupt the circuit before the
door can be opened.

3. Monitor switch 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 Microwave Measurement Procedure.)

Latch Hook

Latch Switch

Lever A

Latch Switch

Lever B

Latch Switch

Lever C

Latch Head

Latch Head

Handle

Lever

Door

Handle

Latch

Lever

Monitor
Switch

1st. Interlock Switch

2nd. Interlock Relay 
Control Switch

Latch Switch