TROUBLESHOOTING GUIDE
Never touch any part in the circuit with your hand or an uninsulated tool while the power supply is connected.
When troubleshooting the microwave oven, it is helpful to follow the Sequence of Operation in performing the checks. Many of the possible causes of trouble will require that a specific test be performed. These tests are given a procedure letter which will be found in the "Test Procedure "section.
IMPORTANT: If the oven becomes inoperative because of a blown monitor fuse, check the monitor switch, primary interlock relay (RY1), door sensing switch and secondary interlock switch before replacing the monitor fuse. If monitor fuse is replaced, the monitor switch must also be replaced. Use part
IMPORTANT: Whenever troubleshooting is performed with the power supply cord disconnected. It may in, some cases, be necessary to connect the power supply cord after the outer case has been removed, in this event,
1.Disconnect the power supply cord, and then remove outer case.
2.Open the door and block it open.
3.Discharge high voltage capacitor.
4.Disconnect the leads to the primary of the power transformer.
5.Ensure that the leads remain isolated from other components and oven chassis by using insulation tape.
6.After that procedure, reconnect the power supply cord.
When the testing is completed
1.Disconnect the power supply cord, and then remove outer case.
2.Open the door and block it open.
3.Discharge high voltage capacitor.
4.Reconnect the leads to the primary of the power transformer.
5.Reinstall the outer case (cabinet).
6.Reconnect the power supply cord after the outer case is installed.
7.Run the oven and check all functions.
TEST PROCEDURE
POSSIBLE CASE
AND
DEFECTIVE PARTS
CONDITION | PROBLEM |
| Home fuse or circuit breaker blows when |
OFF | power cord is plugged into wall outlet. |
| |
CONDITION | Monitor fuse blows when power cord is |
| |
| plugged into wall outlet. |
| Oven lamp does not light, and fan motor |
| and antenna motor do not operate. |
| Oven does not go into cook cycle when |
| Light Up Dial turned. |
| Oven seems to be operating but little or |
COOKING | no heat is produced in oven load. (Food |
CONDITION | incompletely cooked or not cooked at all |
| at end of cook cycle.) |
| Oven goes into a cook cycle but |
| extremely uneven heating is produced in |
| oven load (food). |
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A | B | C | D | E | F | F | G | H | I | J | K | L | RE | RE | RE | RE | RE | CK | CK | CK |
MAGNETRON | POWER TRANSFORMER | H.V. RECTIFIER ASSEMBLY | HIGH VOLTAGE CAPACITOR | THERMAL | SECONDARY INTERLOCK SWITCH | PRIMARY INTERLOCK SYSTEM | MONITOR SWITCH | MONITOR FUSE | NOISE FILTER | CONTROL PANEL | RELAY (RY2) | FOIL PATTURN ON P.W.B. | OVEN LAMP OR SOCKET | COOLING FAN MOTOR | ANTENNA MOTOR | SHORTED IN POWER CORD | SHORT OR OPENED WIRING | WRONG OPERATION | LOW VOLTAGE | DIRTY OVEN CAVITY |
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