R-3C57
15
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
N
NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the noise
filter. Using an ohmmeter, check between the terminals
as described in the following table.
L (min)
Cx
±
20%
Cy
±
20%
1.0 mH
0.068
µ
F
0.0022
µ
F
N
L
C
L
L
C
WHT
RED
X
Y
MEASURING POINT
INDICATION OF OHMMETER
Between N and L
Open circuit
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.
36
VRS1
(J1)
(J2)
5
CN-A
1
a
b
c
d
LOT NO.
To protect the electronic circuits, this model is provided with a fine foil pattern added to the primary on
the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given
below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
STEPS
OCCURANCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present at
Check supply voltage and oven power cord.
POWER terminal of CPU connector (CN-H)
2
The rated AC voltage is present at primary
Low voltage transformer or secondary circuit defective.
side of low voltage transformer.
Check and repair.
3
Only pattern at "a" is broken.
*Insert jumper wire J1 and solder.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
4
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
(CARRY OUT 3D CHECKS BEFORE REPAIR)
NOTE: *At the time of making these repairs, make
a visual inspection of the varistor. check
for burned damage and examine the
transformer with a tester for the presence
of layer short-circuit (check primary coil
resistance). If any abnormal condition is
detected, replace the defective parts.
CARRY OUT 4R CHECKS.
M
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 25.0V D.C.
Oven lamp / Turntable motor / Cooling fan motor
RY2
APPROX. 29.0V D.C.
Power transformer
CARRY OUT 4R CHECKS.
