Sharp R-4P58 Service Manual page 19

TEST PROCEDURES (CONT'D)
PROCEDURE é ;
LETTER | COMPONENT TEST
clearing with a beep the key unit is fauity and must be replaced. If the control unit does not respond,
it is a faulty and must be replaced. If a specific pad does not respond, the above method may be used
(after clearing the control unit) to determine if the control unit or key pad is at fault.
CARRY OUT 4R CHECKS.
KEY UNIT
O RELAY TEST
ay CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 7 and 3 of the4 pin connector {A) onthe
control unit with an A.C. voltmeter.
The meter should indicate 230 volts, if not check oven circuit.
Relay Test
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
convection cooking operation or grill operation.
DC. voltage indicated .......... Defective relay.
DC. voltage not indicated .... Check diode which is connected to the relay coil. If diode is good,
cS control unit is defective.
CARRY OUT 4R CHECKS.
P PROCEDURES TO BE TAKEN WHEN THE FOIL PATTERN ON THE PRINTED WIRING
BOARD (PWB) OPEN
To protect the electronic circuits, this model is provided with a fine foil pattern added to the input circuit
on the PWB, this foil pattern acts as a fuse. If the foil pattern is open, follow the troubleshooting guide
given below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
The rated Ne voltage is noi present at Check supply voliage and oven power cord.
SS ae
tg rated AC voltage is present at — Low voltage Eeusionner or secondary circuit defective.
;
Only pattern at "a" is broken. "Insert jumper wire J1 and solder.
(CARRY OUT 3D CHECKS BEFORE REPAIR)
4 Pattern ai "a" and "b" are broken. "Insert the coil RCILF2003YAZZ between "c" and "d".
(CARRY OUT 3D CHECKS BEFORE REPAIR)
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