Sharp r-8580 manual Procedure Letter Test Procedures CONT’D Component Test, Power Transformer Test

Page 16

R-8680

PROCEDURE

LETTER

TEST PROCEDURES (CONT’D)

COMPONENT TEST

3.Water container should be one (1) litre beaker made of Pyrex glass and its diameter approxi- mately 12 cm.

4.Room temperature should be around 20 “C.

5.Power supply voltage should be specification voltage.

POWER TRANSFORMER TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPO- NENTS OR WIRING.

Disconnect the primary input terminals and measure the resistance of the transformer with an ohmmeter. Check for continuity of the coils with an ohmmeter. On the R x 1 scale, the resistance of the primary coil should be approx. 1.6 ohm and the resistance of the high voltage coil should be approximately 74 ohms; the resistance of the filament coil should be less than 1 ohm.

(HIGH VOLTAGES ARE PRESENT TO HIGH VOLTAGE TERMINAL, SO DO NOT ATTEMPT TO MEASURE THE FILAMENT AND HIGH VOLTAGE.)

C

HIGH VOLTAGE RECTIFIER AND RECTIFIER TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPO- NENTS OR WIRING.

HIGH VOLTAGE RECTIFIER TEST

Isolate the high voltage rectifier from the circuit. Using the highest ohm scale of the meter read the resistance across the terminals and observe, reverse the leads to the high voltage rectifier terminals and observe meter reading. If a short is indicated in both directions, or if an infinite resistance is read in both directions, the high voltage rectifier is probably defective and should be replaced.

RECTIFIER TEST

Isolate the rectifier from the circuit. Using the highest ohm scale of the meter, read the resistance across the terminals, reverse the leads to the rectifier terminals and observe meter reading. If an infinite resistance is read in both directions, the rectifier is good.

If a short is indicated in either direction, the one is probably defective and should be replaced.

D

HIGH VOLTAGE CAPACITOR TEST

DISCHARGE THE HIGH VOLTAGE CAPACITOR BEFORE TOUCHING ANY OVEN COMPO- NENTS OR WIRING.

If the capacitor is open, no high voltage will be available to the magnetron. Disconnect input leads and check for short or open, between the terminals using an ohmmeter.

Checking with a high ohm scale, if the high voltage capacitor is normal, the meter will indicate

continuity

for

a short

time

and

should indicate

approximately

IOM R

once the capacitor is

charged.

If the

above

is not

the

case, check the

capacitoi’with

an ohmmeter

to see if it is shorted

between the terminals. If it is shorted, replace the capacitor.

 

 

 

 

 

 

 

 

 

 

(RD82603U)

E

 

 

 

 

SWITCH

TEST

 

 

Isolate the switch and check the contacts by using an ohmmeter using the following table. If improper operation is indicated, make the necessary switch adjustment or replacement.

 

 

 

Table:

Switch

Connection

 

 

Connection

Common Terminal-Normally

Open

Terminal

Common Terminal-Normally Close Terminal

Operation

 

(COM)

 

(NO)

 

(COW

(NC)

 

 

 

 

 

 

 

Plunger

released

Open

circuit

 

 

Close

circuit

Plunger

pushed

Closed

circuit

 

 

Open

circuit

 

 

 

 

 

 

 

(RD82701U)

15

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Contents Sharp Microwave Radiation Sharpcorporatkn OSAKA, JapanConvection Microwave Oven 8580Specification Product DescriptionAuto-TouchTM Control Panel Operation Description of Operating SequenceOFF Condition Cooking ConditionConvection Cooking Condition Automatic MIX Cooking ConditionPreheating Condition Convection Cooking ConditionSensor Cooking Condition Compu CookEasy Defrost Cooking Cooking SequenceFigure O-l. Oven Schematic-OFF Condition 240V-50Hz G-4Figure O-3. Oven Schematic-Convection Cooking Condition Description and Function of Components Convection Cooking System Convection HeaterDamper OPEN-CLOSE Mechanism Servicing Problem Possible Cause Test Procedure CorrectionOFF Condjtion Problem Possible Cause Test Procedure or Correction Nents Defective Convection Heater Procedure RelayRY4 Unit Test Procedures Letter Component Magnetron Assembly Test Microwave Output PowerProcedure Letter Test Procedures CONT’D Component Test Power Transformer TestSwitch Test High Voltage Rectifier and Rectifier TestTest Procedures CONT’D Letter Component Monitor Switch Test Blown FuseTEMP. Fuse Test Thermal CUT-OUTProcedure Letter Damper Switch TestThermistor Test Damper Motor TestTest Procedures CONT’O Letter Component Relay Unit Relay Symbol Operational Connected Components VoltageKEY Unit Test Checking the initial sensor cooking condition Testing Method for AH Sensor AND/OR Control UnitWater load cooking test Sensor Dummy Resistor Circuit Steps Occurance Cause or CorrectionOutline of Touch Control Panel Touch Control Panel AssemblyLSI Description of LSJ LSI IZA096DRSeqment Data signal Seqment Data SiqnalKev strobe siqnal Internal clock oscillation frequency input settinqSignal to Sound Signal svnchronized with commercial source frequencv50HzPower source voltage Magnetron High-voltaae Circuit driving SignalDamper motor relav driving signal Input signal which communicates the door open/closeSignal cominq from touch kev Signal coming from touch keyTemperature measurement input Oven Thermistor Sensor InuutRI4 Terminal For Manufacture TestAbsolute Humidity Sensor CircuitOther Precautions ServicingShapes of Electronic Components Servicing of Touch Control PanelComponent Replacement and Adjustment Procedure Power Transformer RemovalHigh Voltage Capacitor Removal Turntable Motor AND/OR Coupling RemovalConvection Motor Removal Magnetron RemovalCooling FAN Motor Removal Upper Latch Switch / Monitor Switch Removal Lower Latch Switch and Stop Switch RemovalDamper RemovalControl Panel Assembly and CPU Unit Removal CPU Unit and KEY UnitDoor Replacement Door Replacement and AdjustmentDoor Adjustment Microwave Measurement Preparation for TestingRequirement 11II II II II OIL 8580 Figure S-3. Printed Wiring Board II IParts List AY AK AF AHQ8L RR-DZ561PDREOAT AH FOVN-A090WRYO AG AD 11 AA 13 AA Ii AA Replacement Parts List 8580 Control Panel Parts Door Assembly Miscellaneous ‘Y \‘\Packing and Accessories 8580 8580 Sharp
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