Sharp R-677W User Manual

R-677 - 17
PROCEDURE
LETTER
COMPONENT TEST
I
NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of noise filter.
Using an ohmmeter, check between the terminals as
described in the following table.
MEASURING POINTS INDICATION OF OHMMETER
Between N and L Approx. 680 kΩ
Between terminal N and WHITE Short circuit
Between terminal L and RED Short circuit
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT
4R CHECKS.
LINE BYPASS
CAPACITOR
4700p/250V
LINE BYPASS
CAPACITOR
4700p/250V
NOISE SUPPRESSION COIL
RESISTOR 680K/0.5W
10M/0.5W
LINE CROSS CAPACITOR
0.22µ/250V
F1:
FUSE 15A
F2: FUSE F8A
NOISE 
FILTER
LN
WHT RED
J MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two
terminals as described in the table below.
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 370 Ω
Turntable motor Approximately 14.9 kΩ
If incorrect readings are obtained, replace the motor.
CARRY OUT
4R CHECKS.
K GRILL HEATING ELEMENT (TOP) AND BOTTOM HEATING ELEMENT TEST
CARRY OUT 3D CHECKS.
Before carrying out the following tests make sure the heating element is cooled completely.
1. Resistance of heating element.
Disconnect the wire leads to the heating element to be tested. Using ohmmeter with low resistance
range. Check the resistance across the terminals of the heating element as described in the
following table.
Table: Resistance of heating element
Parts name Resistance
Grill heating element (top) Approximately 76 Ω
Bottom heating element Approximately 132 Ω
2. Insulation resistance.
Disconnect the wire leads to the heating element to be tested. Check the insulation resistance
between the element terminal and cavity using a 500V - 100MΩ insulation tester. The insulation
resistance should be more than 10 MΩ in the cold element.
If the results of above test 1 and/or 2 are out of above specifications, the heating element is probably
faulty and should be replaced.
CARRY OUT 4R CHECKS.
TEST PROCEDURES CONT...

Sharp R-677W Specifications

General

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