17
R-22GV
R-22GT
R-23GT
R-24GT
TEST PROCEDURES (CONT'D)
PROCEDURE
LETTER
COMPONENT TEST
When replacing thermal cut-out, check plastic contents around thermal cut-out. If they are damaged,
replace them with each defective thermal cut-out.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE THE THERMAL CUT-OUT.
K
MAGNETRON THERMISTOR TEST
Disconnect connector-H from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp.
59˚F (15˚C)
68˚F (20˚C)
77˚F (25˚C)
Resistance
Approx. 15.91 k
Ω
Approx. 13.04 k
Ω
Approx. 10.74 k
Ω
If the meter does not indicate above resistance, replace the thermistor.
OVEN THERMISTOR TEST
Disconnect connector-B from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp.
59˚F (15˚C)
68˚F (20˚C)
77˚F (25˚C)
Resistance
Approx. 77.45 k
Ω
Approx. 61.47 k
Ω
Approx. 49.12 k
Ω
If the meter does not indicate above resistance, replace the thermistor.
INTAKE THERMISTOR TEST
Disconnect connector-D from the CPU unit. Measure the resistance of the thermistor with an ohmmeter.
Connect the ohmmeter leads to the leads of the thermistor.
Room Temp.
59˚F (15˚C)
68˚F (20˚C)
77˚F (25˚C)
Resistance
Approx. 15.88 k
Ω
Approx. 13.03 k
Ω
Approx. 10.74 k
Ω
If the meter does not indicate above resistance, replace the thermistor.
L
TOUCH CONTROL PANEL ASSEMBLY TEST
The touch control panel consists of circuits including semiconductors such as LSI, IC, 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, troubleshooting by unit replacement is described 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 the pads, sometimes a pad produces no signal.
2. Control Unit
The following symptoms may indicate a defective control unit. Replace the control unit.
2-1 Programming problems.
a) When touching the pads, a certain group of pads 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.
2-3 Other possible problems caused by defective control unit.
a) Buzzer does not sound or continues to sound.
b) Cooking is not possible.
Note: When defective components, (the Control Unit or Key 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.
