Service manual

R-204(W)
13
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
MEASURING POINTS INDICATION OF OHMMETER
Between N and L Approx. 680 kΩ
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.
I 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.
Table: Resistance of Motor
Motors Resistance
Fan motor Approximately 400 Ω
Turntable motor Approximately 12 kΩ
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
FUSE
M8A
F1:
N
L
LINE CROSS CAPACITOR
0.068µ/AC250V
NOISE SUPPRESSION COIL
LINE BYPASS
CAPACITOR
0.0022µ/AC250V
LINE BYPASS
CAPACITOR
0.0022µ/AC250V
NOISE FILTER
WHT RED
CARRY OUT 3D CHECKS.
If the high voltage fuse is blown, there could be a short in the high voltage rectifier or the magnetron.
Check them and replace the defective parts and the high voltage fuse.
CARRY OUT 4R CHECKS.
CAUTION: ONLY REPLACE HIGH VOLTAGE FUSE WITH THE CORRECT VALUE REPLACE-
MENT.
J HIGH VOLTAGE FUSE TEST
K CONTROL PANEL ASSEMBLY TEST
The control panel consists of circuits including semiconductors such as LSI, ICs, etc. Therefore, unlike
conventional microwave ovens, proper maintenance can not be performed with only a voltmeter and
ohmmeter.
In this service manual, troubleshooting by replacement is described according to the symptoms
indicated.
1. Control Panel
The following symptoms indicate a defective control unit.
1-1 In connection with LEDs
a) At a certain LED, all or some LEDs do not light up.
b) At a certain LED, brightness is low.
c) Only one LED does not light up.
d) All or some LEDs continue to light up.
e) A certain group of LEDs do not light up.
f) The LEDs flicker.
1-2 Tact switch
a) When touching a tact switch, a tact switch produces no signal.
1-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Cooking is not possible.
c) Cooking time can not be set.
d) Power level can not be set.