R-9HlO
TEST PROCEDURES (CONT’D)
PROCEDURE
LETTER
COMPONENT TEST
TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, ICs, etc.
Therefore, unlike conventional microwave ovens, proper maintenance cannot be performed with
only a voltmeter and ohmmeter.
In this service manual, the touch control panel assembly is di-
vided into two units, Control Unit and Key Unit and troubleshooting by unit replacement is de-
scribed according to the symptoms indicated.
1. Key Unit.
The following symptoms indicate a defective key unit. Replace the key unit.
a) When touching the pads, a certain pad produces no signal at all.
b) When touching a number pad, two figures or more are displayed.
c) When touching the pads, sometimes a pad produces no signal.
2. Control Unit
The following symptoms indicate a defective control unit. Replace the control unit.
2-l In connection with pads.
a) When touching the pads, a certain group of pads do not produce a signal.
b) When touching the pads, no pads produce a signal.
2-2 In connection with indicators
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.
e) Wrong figure appears.
f) A certain group of indicators do not light up.
g) The figure of all digits ficker.
2-3 Other possible troubies caused by delx. je control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
d) Proper temperature measurement is not obtained.
Note: When defective components, the Control Unit or Key Unit are replaced, the defective part
or parts must be properly packed for return in the shipping carton, with its cushion mate-
rial, in which the new replacement part was shipped to you.
(RD82SOl U)
RELAY TEST
Remove the outer case and check voltage between Pin Nos.
1 and 3 of the 3-pin connector (A)
on the control unit with an A.C. voltmeter.
The meter should indicate 240 volts, if not check oven circuit.
Shut-off,Cook and Heater Relay Test
These relays are operated by D.C. voltage.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking or convection
cooking operation.
DC. voltage indicated
. . . . . . . . . . Defective
relay.
DC. voltage not indicated
. . . . . . ..Check diode which is connected to the relay coil. If diode is
good, control unit is defective.
RELAY SYMBOL
OPERATIONAL CONNECTED COMPONENTS
VOLTAGE
RYl Approx. 13 V.D.C
Oven lamp and Turntable motor
RY2 (COOK)
Approx. 13 V.D.C
Power transformer
RY3 (HEATER) Approx. 13 V.D.C
Heating element
RY4
Approx. 14 V. D.C.
Damper motor
RY5
Approx. 14 V.D.C.
Convection motor
RY6
Approx. 13 V.D.C
Cooling fan motor
(RD82ROW)
18
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