Sharp R-677W User Manual

R-677 - 16
PROCEDURE
LETTER
COMPONENT TEST
E SWITCH TEST
CARRY OUT 3D CHECKS.
Isolate the switch to be tested and using an ohmmeter check between the terminals as described
in the following table.
COM; Common terminal,
NO; Normally open terminal
NC; Normally close terminal
If incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R CHECKS.
F THERMAL CUT-OUT TEST
Table: Terminal Connection of Switch
Plunger Operation COM to NO COM to NC
Released Open circuit Short circuit
Depressed Short circuit Open circuit
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the thermal cut-out. Then using an ohmmeter, make a
continuity test across the two terminals as described in the below.
Table: Thermal Cut-out Test
Temperature of "ON" Temperature of "OFF" Indication of ohmmeter
Parts Name condition (closed circuit). condition (open circuit). (When room temperature
(˚C) (˚C) is approx. 20˚C.)
Thermal cut-out 145˚C Cuts back in at 115˚C. Above 145˚C Closed circuit
Thermal cut-out 150˚C Cuts back in at 130˚C. Above 150˚C Closed circuit
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out TC1 (HVT) indicates that the high voltage transforner has overheated,
this may be due to resistricted ventilation, cooling fan failure or a fault condition within the high voltage
transformer or HV. circuit.
An open circuit thermal cut-out TC2 (OVEN) indicates that the food in the oven cavity may catch fire,
this may be due to over heating produced by improper setting of the cooking timer or failure of the
control panel.
CARRY OUT 4R CHECKS.
G BLOWN FUSE 20A (F1)
CARRY OUT 3D CHECKS.
If the fuse 15A is blown, there could be a shorts or a ground in electrical parts or wire harness. Check
them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse
20A with the correct value replacement.
H BLOWN FUSE F8A (F2)
CARRY OUT 3D CHECKS.
If the fuse F8A (F2) is blown when the door is opened, check the primary latch switch, monitor switch
and monitor resistor.
If the fuse F8A (F2) is blown by incorrect door switching replace the defective switch(es) and the fuse
F8A (F2).
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse with the correct value replacement.
TEST PROCEDURES CONT...

Sharp R-677W Specifications

General

Brand	Sharp
Model	R-677W
Category	Microwave Oven
Language	English