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R-334 - 18
PROCEDURE
LETTER
COMPONENT TEST
J
MOTOR WINDING TEST
TEST PROCEDURES (CONT.)
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.
terminals as described in the table below.
Table: Resistance of Motor
Motors
Resistance
Fan motor
Approximately 218
Ω
Turntable motor
Approximately 15.5k
Ω
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS
K
LIVE TEST FOR MOTOR WINDINGS
CAUTION: The following procedure requires the oven to be connected to the supply and should
only be used if the relevant "cold" checks for the motor under test are inconclusive.
1. CARRY OUT 3D CHECKS
2. Disconnect the leads from the primary of the power transformer. Make sure that the leads remain
2. Disconnect the leads from the primary of the power transformer. Make sure that the leads remain
isolated from other oven components and chassis. (Use insulation tape if necessary.)
3. Connect a voltmeter, set to 250V AC, across the motor terminals. (Refer to the relevant motor test
procedure or pictorial diagram for the correct terminal numbers.)
4. Arrange the meter in a position where it can be read during the test.
(Do not touch the meter, meter leads or oven circuitry while the oven is active.)
5. Close the oven door.
6. Set the power level to HIGH and set the relevant timer for about three (3) minutes.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS
9. Remove test meter leads.
10. Reconnect the leads to the primary of the power transformer.
6. Set the power level to HIGH and set the relevant timer for about three (3) minutes.
7. Note the reading on the meter and carefully observe the motor under test to see if it is turning.
8. CARRY OUT 3D CHECKS
9. Remove test meter leads.
10. Reconnect the leads to the primary of the power transformer.
If a reading of the line voltage was obtained (step 7) but the motor was not turning then it is faulty and
should be replaced. If the meter indicated that no supply was present then the wiring to the motor should
be checked for continuity.
should be replaced. If the meter indicated that no supply was present then the wiring to the motor should
be checked for continuity.
L
TOUCH CONTROL PANEL ASSEMBLY TEST
Do not touch the electrical parts and the printed wiring board to prevent an electric
CAUTION
shock. Because the control unit is " TRANSLESS CIRCUIT " and all electrical parts
are used at A.C. line voltage.
are used at A.C. line voltage.
The touch 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, the touch control panel assembly is in one unit and troubleshooting by unit
replacement is described according to the symptoms indicated.
Control Panel.
unlike conventional microwave ovens, proper maintenance can not be performed with only a voltmeter
and ohmmeter.
In this service manual, the touch control panel assembly is in one unit and troubleshooting by unit
replacement is described according to the symptoms indicated.
Control Panel.
The following symptoms indicate a defective control unit.
1. Tact Switch.
The following symptoms indicate a defective tact switch. Replace the tact switch.
a) When touching a tact switch, a certain tact switch produces no signal at all.
b) When touching a tact switch, sometimes a tact switch produces no signal.
b) When touching a tact switch, sometimes a tact switch produces no signal.
2. In connection with tact switches.
a) When touching a tact switch, a certain group of tact switch do not produce a signal.
b) When touching a tact switch, no tact switch produce a signal.
b) When touching a tact switch, no tact switch produce a signal.
3. Display problems.
a) At a certain digit, all or some segments do not light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
b) At a certain digit, brightness is low.
c) Only one indicator does not light up.
d) The corresponding segments of all digits do not light up; or they continue to light up.
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