Sharp R-2275, Руководство по обслуживанию

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13
R-2275
R-2285
PROCEDURE
LETTER
COMPONENT TEST
TEST PROCEDURES (CONT'D)
G SPECIAL FUSE / WEAK POINT (F1) TEST
CARRY OUT 3D CHECKS
If the special fuse / weak point F1 is blown, there could be a shorts or grounds in electrical parts or wire
harness.
Check them and replace the defective parts or repair the wire harness.
CARRY OUT 4R CHECKS
CAUTION: Only replace special fuse / weak point with the correct value replacement.
H FUSE F6.3A (F2) TEST
CARRY OUT 3D CHECKS
If the fuse F2 F6.3A is blown when the door is opened, check the latch switch, monitor switch and monitor
resistor.
If the fuse F2 F6.3 is blown by incorrect door switching replace the defective switch(es) and the fuse F2
F6.3A.
CARRY OUT 4R CHECKS
CAUTION: Only replace fuse with the correct value replacement.
I TEMPERATURE FUSE OR THERMAL CUT-OUT TEST
CARRY OUT 3D CHECKS
Disconnect the leads from the terminals of the temp. fuse or thermal cut-out. Then using an ohmmeter,
make a continuity test across the each two terminals as described in the table below.
CARRY OUT 4R CHECKS
Table: Temperature Fuse or Thermal Cut-out Test
Temperature of “ON” Temperature of “OFF” Indication of ohmmeter
Parts Name condition (closed circuit). condition (open circuit). (When room temperature
(˚C) (˚C) is approx. 20˚C.)
Oven temp. fuse 150˚C This is not resetable type. Above 150˚C Closed circuit
Thermal cut-out 145˚C Below -20˚C Above 145˚C Closed circuit.
Thermal cut-out 115˚C Below -20˚C Above 115˚C Closed circuit
If incorrect readings are obtained, replace the temp. fuse or thermal cut-out.
An open circuit oven temp. fuse 150˚C indicates that the oven cavity has over heated, this may be due
to no load operation.
An open circuit thermal cut-out 145˚C indicates that the magnetron has overheated, this may be due to
resistricted ventilation, cooling fan failure or a fault condition within the magnetron or HV circuit.
An open circuit blower motor thermal cut-out 115˚C indicates the blower motor winding has overheated,
this may be due to resisted ventilation or locked cooling fan.
J MONITOR RESISTOR AND SURGE RESISTOR TEST
Table: Resistance
Resistor Resistance
Monitor resistor Approx. 4.3
Ω
Surge resistor Approx. 10
Ω
CARRY OUT 3D CHECKS
Disconnect the leads from the monitor resistor or surge resistor.
Using an ohmmeter and set on a low range.
Check between the terminals of the monitor resistor or surge resistor as described in the following table.
If incorrect readings are obtained, replace the monitor resistor or surge resistor.
CARRY OUT 4R CHECKS