Read Sharp R-2398G Service Manual online
15
R-2398
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
b) For a certain digit, brightness is low.
c) Only one indicator does not light.
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 flicker.
c) Only one indicator does not light.
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 flicker.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Cooking is not possible.
b) Cooking is not possible.
CARRY OUT 3D CHECKS.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is
making good contact, verify that the door sensing switch (stop switch ) operates properly; that is the
contacts are closed when the door is closed and open when the door is open. If the door sensing switch
(stop switch ) is good, disconnect the flat ribbon cable that connects the key unit to the control unit and
make sure the door sensing switch is closed (either close the door or short the stop switch connector
). Use the key unit matrix indicated on the control panel schematic and place a jumper wire between
the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit
responds by clearing with a beep, the key unit is faulty and must be replaced. If the control unit does
not respond, it is faulty and must be replaced. If a specific pad does not respond, the above method
may be used (after clearing the control unit ) to determine if the control unit or key pad is at fault.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is
making good contact, verify that the door sensing switch (stop switch ) operates properly; that is the
contacts are closed when the door is closed and open when the door is open. If the door sensing switch
(stop switch ) is good, disconnect the flat ribbon cable that connects the key unit to the control unit and
make sure the door sensing switch is closed (either close the door or short the stop switch connector
). Use the key unit matrix indicated on the control panel schematic and place a jumper wire between
the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit
responds by clearing with a beep, the key unit is faulty and must be replaced. If the control unit does
not respond, it is faulty and must be replaced. If a specific pad does not respond, the above method
may be used (after clearing the control unit ) to determine if the control unit or key pad is at fault.
CARRY OUT 4R CHECKS.
P
KEY UNIT TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 5 and 7 of the connector (A) on the control
unit with an A.C. voltmeter. The meter should indicate 230~240 volts, if not check control unit circuity.
unit with an A.C. voltmeter. The meter should indicate 230~240 volts, if not check control unit circuity.
RY1, RY3 and RY4 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 operation.
These relays are operated by D.C. voltage.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated .............................Defective relay.
DC. voltage not indicated ....................... Check diode which is connected to the relay coil. If
DC. voltage not indicated ....................... Check diode which is connected to the relay coil. If
diode is good, control unit is defective.
RELAY SYMBOL
OPERATIONAL VOLTAGE
CONNECTED COMPONENTS
RY1
APPROX. 19.0V D.C.
Oven lamp, Blower motor and Stirrer motors
RY3
APPROX. 16.0V D.C.
High voltage transformer 1
RY4
APPROX. 18.0V D.C.
High voltage transformer 2
CARRY OUT 4R CHECKS.
Q
RELAY TEST
SET
3
4
5
6
7
8
9
0
2
CHECK
SIGNAL
START
STOP /
CLEAR
CLEAR
1
11
12
13
14
15
16
19
20
17
18
DOUBLE
QUANTITY
EXPRESS
DEFROST
DEFROST
SELECT
TIME
SELECT
POWER
G12
G11
G10
G 9
G 8
G 7
G 6
G 5
G 4
G 3
G 2
G 1
R
PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD(PWB) IS OPEN
BOARD(PWB) IS OPEN
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.
PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide given below
for repair.
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