Read Sharp R-2498G (serv.man2) Service Manual online
15
R-2498G
L (min)
Cx
±
20%
Cy
±
20%
0.5mH
0.22
µ
F
4700 pF
MEASURING POINT
INDICATION OF OHMMETER
Between N and L
Open circuit
Between terminal N and WHITW
Short circuit
Between terminal L and BLK
Short circuit
If incorrect readings are absorbed, replace the noise filter.
CARRY OUT 4R CHECKS.
L
N
L
L
F1
Cy
BLK
WHT
Cx
N
CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI 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 divided into two units, Control Unit
and Switch Unit, troubleshooting by unit replacement is described according to the symptoms indicated.
1. Switch Unit
conventional microwave ovens, proper maintenance cannot be performed with only a voltmeter and
ohmmeter. In this service manual, the touch control panel assembly is divided into two units, Control Unit
and Switch Unit, troubleshooting by unit replacement is described according to the symptoms indicated.
1. Switch Unit
The following symptoms indicate a defective switch unit. Replace the switch unit.
a) When touching the select buttons, a certain button produces no signal at all.
b) When touching the select buttons, sometimes a button produces no signal.
a) When touching the select buttons, a certain button produces no signal at all.
b) When touching the select buttons, sometimes a button produces no signal.
2. Control Unit
The following symptoms may indicate a defective control unit. Replacing the control unit.
2-1 Programming problems.
a) When touching the select buttons, a certain group of buttons do not produce a signal.
2-2 Display problems.
a) For a certain digit, all or some segments do not light up.
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.
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.
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.
Note: When defective components, (the Control Unit or Switch Unit) are replaed, the defective part
or parts must be properly packed for return in the shipping carton. with its cushion material, in
which the new replacement part was shipped to you.
which the new replacement part was shipped to you.
O
SWITCH UNIT TEST
1. CARRY OUT 3D CHECKS.
2. Remove the switch unit from the control panel, referring to control panel removal.
3. To test the switches (SW1-SW5) on the switch unit, check between the terminals of the connector
2. Remove the switch unit from the control panel, referring to control panel removal.
3. To test the switches (SW1-SW5) on the switch unit, check between the terminals of the connector
CN-F as described in the following table by using ohmmeter when the switches are released and
depressed.
depressed.
Switches
Terminals
Released
Depressed
SW1
F1 - F4
O.C.
S.C.
SW2
F1 - F5
O.C.
S.C.
SW3
F2 - F4
O.C.
S.C.
SW4
F2 - F5
O.C.
S.C.
SW5
F3 - F4
O.C.
S.C.
4. If incorrect readings are obtained, replace the defective switch.
5. CARRY OUT 4R CHECKS.
5. CARRY OUT 4R CHECKS.
O.C. : Open Circuit
S.C. : Short Circuit
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
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