18
R-84ST -
G
THERMAL CUT-OUT TEST
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.
CARRY OUT 4R CHECKS
Table: Thermal Cut-out Test
Temperature of
Temperature of
Indication of
"ON" condition
"OFF" condition
ohmmeter
Parts Name
(closed circuit).
(open circuit).
(When room
(˚C)
(˚C)
temperature is
approx. 20˚C.)
Thermal cut-out
Below 130˚C
Above 150˚C
Closed circuit
150˚C TC1
Thermal cut-out
This is not resetable
Above 125˚C
Closed circuit
125˚C TC2
type
H
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.
I
NOISE FILTER TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the terminals of
noise filter.
Using an ohmmeter, check between the ter-
minals as described in the following table.
MEASURING POINTS
INDICATION OF OHMMETER
Between N and L
Approx. 680 k
Ω
Between terminal N and WHITE
Short circuit
Between terminal L and RED
Short circuit
L (min)
Cx
±
20%
Cy
±
20%
1.0mH
0.22
µ
F
4700pF
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 292
Ω
Turntable motor
Approximately 14.5k
Ω
Convection fan motor
Approximately 290
Ω
If incorrect readings are obtained, replace the thermal cut-out.
An open circuit thermal cut-out (MG) TC2 indicates that the magnetron has overheated, this may be due
to resistricted ventilation, cooling fan failure.
An open circuit thermal cut-out (OVEN) TC1 indicates that the oven cavity has overheated, this may be
due to no load operation.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
R1: 10 M
Ω
±
20%
R2 : 680 k
Ω
±
20%
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT 4R CHECKS
RED
WHT
L
L
R1
L
R2
N
Cx
Cy
R1: 10M ohm
±
20%
R2: 680k ohm
±
20%
F8A
20A
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
