8 – 3
[6] F: NOISE FILTER TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the terminals of the noise filter. Using an ohmmeter,
check between the terminals as described in the following table.
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R CHECKS.
[7] G: 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 divided into two
units, Control Unit and Key Unit, and also the Control Unit is divided into two units, CPU Unit and Power Unit, and troubleshooting by unit 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 control unit assembly.
1) When touching the pads, a certain pad produces no signal at all.
2) When touching a number pad, two figures or more are displayed.
3) When touching the pads, sometimes a pad produces no signal.
2. Control Unit.
The following symptoms indicate a defective control unit. Before replacing the control unit, perform the Key unit test ([8] H) to determine if control
unit is faulty.
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.
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.
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.
MEASURING POINT
INDICATION OF OHMMETER
Between N and L
Approximately 150 k
Between terminal N and WHITE
Short circuit
Between terminal L and RED
Short circuit
RED
WHT
FUSE
F10A
N
L
NOISE SUPPRESSION COIL
LINE BYPASS CAPACITOR
0.0047
μ
F /AC250V
LINE BYPASS CAPACITOR
0.0047
μ
F /AC250V
LINE CROSS CAPACITOR
2.2
μ
F /AC250V
NOISE
FILTER
UNIT
R-350Y(S)
