Read Sharp R-22AMM (serv.man7) Service Manual online
R22AMM
7 – 4
[9] I: TEMPERATURE FUSE TEST
1. CARRY OUT 3D CHECKS.
2. A continuity check across the temperature fuse terminals should indicate a closed circuit unless the temperature of the temperature fuse reaches
specified temperature as shown below.
3. CARRY OUT 4R CHECKS.
CAUTION: IF THE TEMPERATURE FUSE INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE, REPLACE TEMPERATURE FUSE.
[10] J: THERMISTOR TEST
CARRY OUT 3D CHECKS.
Follow the procedures below for each thermistor.
Disconnect the connector of the thermistor from the switch harness. Measure the resistance of the magnetron thermistor with an ohmmeter. Connect
the ohmmeter leads to the leads of the thermistor.
the ohmmeter leads to the leads of the thermistor.
Resistance: Approx. 500 k
Ω -- 1 MΩ
If the meter does not indicate above resistance, replace the thermistor.
CARRY OUT 4R CHECKS.
[11] K: MOTOR WINDING TEST
CARRY OUT 3D CHECKS.
Disconnect the leads from the motor. Using an ohmmeter, check the resistance between the two terminals.
Resistance of Blower motor should be approximately 60
Ω.
Resistance of Antenna motor should be approximately 8.8k
Ω.
If incorrect readings are obtained, replace the motor.
CARRY OUT 4R CHECKS.
[12] L: 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.
terminals as described in the following table.
If incorrect readings are obtained, replace the noise filter unit.
CARRY OUT 4R CHECKS.
[13] M: HIGH VOLTAGE FUSE TEST
CARRY OUT 3D CHECKS.
If the high voltage fuse (F4 or F5) is blown, there could be a short in the high voltage rectifier or the magnetron (MG1 or MG2). Check them and
replace the defective parts and the high voltage fuse (F4 or F5).
replace the defective parts and the high voltage fuse (F4 or F5).
CARRY OUT 4R CHECKS.
CAUTION: Only replace high voltage fuse with the correct value replacement.
Open temperature
Close temperature
Display or
Condition
Check point
Magnetron temperature
fuse (Upper) TF1
fuse (Upper) TF1
150
°C
Non resetable type
EE1
Magnetron MG1 Failure:
Test magnetron MG1 and Blower motor.
Test magnetron MG1 and Blower motor.
Magnetron temperature
fuse (2) (Lower) TF2
fuse (2) (Lower) TF2
EE2
Magnetron MG2 Failure:
Test magnetron MG2 and blower motor.
Test magnetron MG2 and blower motor.
Magnetron temperature
fuses TF1, TF2
fuses TF1, TF2
EE3
Magnetron MG1, MG2 Failure: Test magnetron MG1,
MG2. Check blower motor and ventilation opening.
MG2. Check blower motor and ventilation opening.
Exhaust temperature
fuse TF3
fuse TF3
120
°C
Non resetable type
Oven shut off
Food has been burned in oven.
Temperature of oven inside is very high.
Temperature of oven inside is very high.
MEASURING POINT
INDICATION OF OHMMETER
Between N and L
Approx. 680 k
Ω
Between terminal N and WHITE
Short circuit
Between terminal L and BLK
Short circuit
F 3 : W E AK P OINT
NOIS E F ILT E R
NOIS E S UP P R E S S ION C OIL
DIS C HAR G E R E S IS T OR 680 k 1/2W
DIS C HAR G E R E S IS T OR 10 M 1/2W
LINE C R OS S C AP AC IT OR 0.22μF / AC 250V
LINE C R OS S C AP AC IT OR
10000 pF / AC 250V
LINE C R OS S C AP AC IT OR
10000 pF / AC 250V
L
B LK
WHT
N
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