Sharp R-330DK Service Manual page 20

R- 330DK
R-330DW
PROCEDURE
LETTER
(5) If improper operation is indicated, the control unit is probably defective and should be checked.
M FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
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.
1. Foil pattern check and repairs.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Follow the troubleshooting guide given below for repair.
STEPS
5) Make a visual inspection of the varistor. Check
for burned damage and examine the trans-
former with a tester for the presence of layer
short-circuit (check the primary coil resistance
which is approximately 212
abnormal condition is detected, replace the
defective parts.
6) Reconnect all leads removed from components during testing.
7) Re-install the outer case (cabinet).
8) Reconnect the power supply cord after the outer case is installed.
9) Run the oven and check all functions.
2. Follow the troubleshooting guide given below, if indicator does not light up after above check and
repairs are finished.
1) Disconnect the power supply cord, and then remove outer case.
2) Open the door and block it open.
3) Discharge high voltage capacitor.
4) Disconnect the leads to the primary of the power transformer.
5) Ensure that these leads remain isolated from other components and oven chassis by using
insulation tape.
6) After that procedure, re-connect the power supply cord.
7) Follow the troubleshooting guide given below for repair.
STEPS
8) Disconnect the power supply cord, and then remove outer case.
9) Open the door and block it open.
10) Discharge high voltage capacitor.
11) Reconnect all leads removed from components during testing.
TEST PROCEDURES
1ST STAGE
WEIGHT
LEVEL
0.5lb 70%
OCCURRENCE
1 Only pattern at "a" is broken.
2 Pattern at "a" and "b" are broken.
OCCURRENCE
The rated AC voltage is not present between
1 Pin No. 1 of the 2-pin connector (A) and the
common terminal of the relay RY1.
The rated AC voltage is present at primary
2
side of low voltage transformer.
COMPONENT TEST
2ND STAGE
TIME LEVEL TIME
40sec. 40% 30sec.
*Insert jumper wire J1 and solder.
*Insert the coil RCILF2003YAZZ between "c" and "d".
10%). If any
Check supply voltage and oven power cord.
Low voltage transformer or secondary circuit defective.
Check and repair.
18
CAUSE OR CORRECTION
d
c
b
(J1)
a
CAUSE OR CORRECTION