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R-21ATP
11
TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
K
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 can not 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 Key
Unit and troubleshooting by replacement is described according to the symptoms indicated.
1. Key Unit Note : Check key unit ribbon connection before replacement.
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 divided into two units, Control Unit and Key
Unit and troubleshooting by replacement is described according to the symptoms indicated.
1. Key Unit Note : Check key unit ribbon connection before replacement.
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.
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 Panel
The following symptoms indicate a defective control unit. Before replacing the control unit.
perform the key unit test (Procedure L) to determine if control unit is faulty.
perform the key unit test (Procedure L) to determine if control unit is faulty.
2-1 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.
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 flicker.
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 flicker.
2-3 Other possible troubles caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Clock does not operate properly.
c) Cooking is not possible.
b) Clock does not operate properly.
c) Cooking is not possible.
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.
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 replacement.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is
marking good contact, verify that the 2nd. interlock relay control switch operates properly; that is the
contacts are closed when the door is closed and open when the door is open. If the 2nd. interlock relay
control switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and
make sure the 2nd. interlock relay control switch is closed (either close the door or short the d2nd.
interlock relay control switch connecter). 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 marking
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 a 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.
marking good contact, verify that the 2nd. interlock relay control switch operates properly; that is the
contacts are closed when the door is closed and open when the door is open. If the 2nd. interlock relay
control switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and
make sure the 2nd. interlock relay control switch is closed (either close the door or short the d2nd.
interlock relay control switch connecter). 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 marking
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 a 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.
L
KEY UNIT TEST
CARRY OUT 4R CHECKS.
5
6
3
4
1
11
13
15
19
12
14
16
20
17
18
2
7
8
9
0
SELECT
TIME
SELECT
POWER
STOP/
CLEAR
START
SET
CHECK
SIGNAL
DOUBLE
QUANTITY
EXPRESS
DEFROST
G12
G11
G10
G 9
G 1
G 2
G 3
G 4
G 5
G 6
G 7
G 8
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