R-875/885 -
19
PROCEDURE
LETTER
COMPONENT TEST
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 or give in the oven cavity.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately
293
Ω
Turntable motor
Approximately
15 k
Ω
Convection fan motor
Approximately
288
Ω
J
BLOWN FUSE F1 20A
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.
CARRY OUT 3D CHECKS.
If the fuse F1 20A is blown, there is a shorts or grounds 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
with
the correct value replacement.
K
BLOWN FUSE F2 F8A
CARRY OUT 3D CHECKS.
1. If the fuse F2 F8A is blown when the door is opened, check the monitored latch switch and monitor
switch.
2. If the fuse F2 F8A is blown by incorrect door switching replace the defective switch(es) and the fuse
F2 F8A.
3. If the fuse F2 F8A is blown, there could be shorts in the asymmetric rectifier or there is a ground in
wire harness. A short in the asymmetric rectifier may be occurred due to short or ground in H.V.
rectifier, magnetron, high voltage transformer or H.V. wire. Check them and replace the defective
parts or repair the wire harness.
CARRY OUT 4R CHECKS.
CAUTION: Only replace fuse F2 F8A with the correct value replacement.
F8A
20A
WHT
RED
R1
R2
N
Cx
Cy
L
L
L
L (min)
Cx
±
20%
Cy
±
20%
1.0mH
0.22
µ
F
4700pF
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
If incorrect readings are absorbed, replace the noise filter unit.
CARRY OUT 4R CHECKS.
TEST PROCEDURES