R-212M (serv.man2) - Sharp Home Appliance Service Manual (repair manual). Page 6

R-212M 6

The door can be opened by pulling the door.

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

must be closed.

1. When the oven door is closed, the contacts (COM-NC)

must be opened.

2. When the oven door is opened, the contacts (COM-

NC) must be closed.

3. If the oven door is opened and t he contacts (COM-NO)

of the monitored latch switch (SW1) fail to open, the
fuse F1 blows immediately after closing the contacts
(COM-NC) of the monitor switch (SW2).

CAUTION: BEFORE REPLACING A BLOWN FUSE  F1.

TEST MONITORED LATCH SWITCH (SW1)
AND  MONITOR SWITCH (SW2) FOR
PROPER OPERATION.  (REFER TO CHAP-
TER “TEST PROCEDURE”).

1. The fuse F1 blows when the contacts (COM-NO) of the

monitored latch switch (SW1) remain closed with the
oven door open and when the contacts (COM-NC) of
the monitor switch (SW2) are closes.

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

circuited, the fuse F1 blows to prevent an electric shock
or fire hazard.

The thermostat protects the high voltage transformer
against overheating. If the temperature goes up higher
than 150˚C because the fan motor is interrupted or the
ventilation openings are blocked, the thermostat will cycle,
line voltage to the high voltage transformer will also cycle.
(If operated, check the magnetron for damage.)

The thermal cut-out located on the top of the oven cavity
is designed to prevent damage to the oven, if the food in
the oven catch fire due to over heating produced by
improper setting of cook time or failure of control unit.
Under normal operation, the thermal cut-out remains
closed. However, when abnormally high temperatures are
reached within the oven cavity, the thermal cut-out will
open at 125˚C, causing the oven to shut down. The
defective thermal cut-out must be replaced with a new
one.

The turntable motor drives the turntable roller assembly to
rotate the turntable.

The fan motor drives a blade which draws external cool air.
This cool air is directed through the air vanes surrounding
the magnetron and cools the magnetron. This air is chan-
nelled through the oven cavity to remove steam and
vapours given off from heating food. It is then exhausted
through the exhausting air vents at the rear of the oven
cavity.

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

Latch hook

SW3: Stop switch

Door

SW2: Monitor switch

SW1: Monitored 

latch switch

Latch heads