14
R-312AW
R-312AK
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
N
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING BOARD
(PWB) IS OPEN
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
the primary coil resistance which is ap-
proximately 563
Ω
±
10%). If any abnor-
mal condition is detected, replace the
defective parts.
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.
STEPS
OCCURRENCE
CAUSE OR CORRECTION
1
The rated AC voltage is not present between
Check supply voltage and oven power cord.
Pin No. 3 of the 2-pin connector (A) and the
common terminal of the relay RY2.
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.
4
Pattern at "a" and "b" are broken.
*Insert the coil RCILF2003YAZZ between "c" and "d".
RY2
a
b
c
d
HVT
AC
(COM)
VH
XH
3
3
CN - A
(J1)
