| TEST PROCEDURES |
PROCEDURE |
|
LETTER | COMPONENT TEST |
| f) A certain group of indicators do not light up. |
| g) The figure of all digits flicker. |
Other possible problems caused by defective control unit. | |
| a) Buzzer does not sound or continues to sound. |
| b) Cooking is not possible. |
NKEY UNIT TEST
CARRY OUT 3D CHECKS.
If the display fails to clear when the STOP/CLEAR pad is depressed, first verify the flat ribbon cable is making good contact, verify that the stop switch operates properly; that is the contacts are closed when the door is closed and open when the door is open. If the stop switch is good, disconnect the flat ribbon cable that connects the key unit to the control unit and make sure the stop switch is closed (either close the door or short the stop switch connector ). Use the key unit matrix indicated on the control panel schematic and place a jumper wire between the pins that correspond to the STOP/CLEAR pad making momentary contact. If the control unit responds by clearing with a beep, the key unit is faulty and must be replaced. If the control unit does not respond, it is 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.
G1
G9
G10
G11
G12
G2
G3
G4
177
18
8
199
200
G5
155
166
G6
133
144
G7
111
122
G8
ORELAY TEST
CARRY OUT 3D CHECKS.
Remove the outer case and check voltage between Pin Nos. 3 and 5 of the connector (A) on the control unit with an A.C. voltmeter. The meter should indicate 230 - 240 volts, if not check control unit circuity.
RY1, RY3 and RY4 Relay Test
These relays are operated by D.C. voltage.
Check voltage at the relay coil with a D.C. voltmeter during the microwave cooking operation.
DC. voltage indicated | Defective relay. | ||
DC. voltage not indicated | Check diode which is connected to the relay coil. If | ||
|
| diode is good, control unit is defective. | |
|
|
| |
RELAY SYMBOL | OPERATIONAL VOLTAGE | CONNECTED COMPONENTS | |
RY1 | APPROX. 25.9V D.C. | Oven lamp, Blower motor and Antenna motors | |
RY3 | APPROX. 25.0V D.C. | High voltage transformer (MG1) | |
RY4 | APPROX. 25.0V D.C. | High voltage transformer (MG2) | |
CARRY OUT 4R CHECKS.
PPROCEDURES TO BE TAKEN WHEN THE FUSE ON THE PRINTED WIRING BOARD(PWB) IS OPEN
To protect the electronic circuits, this model is provided with a fine fuse added to the primary on the PWB. If the fuse is open, follow the troubleshooting guide given below for repair.
Problem: POWER ON, indicator does not light up.
CARRY OUT 3D CHECKS.
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