R-2398G. Complete - Sharp Home Appliance Service Manual (repair manual). Page 8

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1. The door release lever is pulled.
2. The upper latch head is lifted up by the linked door

release lever.

3. The head lever is lifted up by the door release lever.
4. The joint lever is lifted up by the head lever.
5. The lower latch head is lifted up by the joint lever.
6. Now both latch heads are lifted up, so they can be

released from the latch hook.

7. Now the door can be opened.

1. When the oven door is closed, the contacts COM-NO

must be closed.

2. When the oven door is opened, the contacts COM-NO

must be opened.

The monitor switch is activated (the contacts opened) the
upper latch head and switch lever A while the door is
closed. The switch is intended to render the oven inopera-
tive by means of blowing the fuse F6.3A when the contacts
of the 1st latch switch fail to open when the door is opened.

Function
1. When the door is opened, the monitor switch contacts

close (to the ON condition) due to their being normally
closed. At this time the 1st latch switch is in the OFF
condition (contacts open) due to their being normally
open contact switches.

2. As the door goes to a closed position, the monitor

switch contacts are opened and 1st latch switch con-
tacts are closed (On opening the door, each of these
switches operate inversely.)

3. If the door is opened and the 1st latch switch contacts

fail to open, the fuse F6.3A blows simultaneously with
closing of the monitor switch contacts.

CAUTION:BEFORE REPLACING A BLOWN FUSE

F6.3A TEST THE 1ST LATCH SWITCH,

MONITOR SWITCH AND MONITOR RESIS-
TOR FOR PROPER OPERATION. (REFER
TO CHAPTER “TEST PROCEDURE”).

The monitor resistor prevents the fuse F6.3A 250V burst-
ing when the fuse F6.3A 250V blows due to the operation
of the monitor switch.

The noise filter assembly prevents radio frequency inter-
ference that might flow back in the power circuit.

If the wire harness or electrical components make a short-
circuit, this fuse F13A blows to prevent an electric shock
or fire hazard.

1. If the wire harness or electrical components are short-

circuited, this fuse blows to prevent an electric shock or
fire hazard.

2. The fuse also blows when 1st latch switch remains

closed with the oven door open and when the monitor
switch closes.

If the wire harness or the high voltage transformers are
short-circuited, these fuses blow to prevent an electric
shock or fire hazard.

The high voltage fuse blows when the high voltage rectifier
or the magnetron is shorted.

The temperature fuses located on the top of the upper and
lower waveguide are designed to prevent damage to the
magnetrons. If an over heated condition develops in the
tube due to blower motor failure, obstructed air ducts, dirty
or blocked air intake, etc., the circuit to the magnetrons are
interrupted. Under normal operation, the temperature
fuses remains closed. However, when abnormally high
temperatures are generated within the magnetrons, the
temperature fuses will open at 150˚C causing the micro-
wave energy to stop. The defective temperature fuses
must be replaced with new rated ones.

The temperature fuse, located on the side of the exhaust
duct assembly, is designed to prevent damage to the oven
by fire. If the food load is overcooked, by either error in
cook time or defect in the control unit, the temperature fuse
will open. Under normal operation, the oven temperature
fuse remains closed. However, when abnormally high
temperatures are generated within the oven cavity, the
oven temperature fuse will open at 120˚C, causing the
oven to shut down. The defective temperature fuse must
be replaced with new rated one.

Latch head

Monitor switch

Latch hook

1st. latch switch

2nd. latch switch

Stop switch

3rd. latch switch

Latch head

Joint lever

Door release
lever

Head lever