User Manual
Table Of Contents
- PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY
- WARNING TO SERVICE PERSONNEL
- MICROWAVE MEASUREMENT PROCEDURE
- FOREWORD AND WARNING
- PRODUCT DESCRIPTION
- GENERAL INFORMATION
- OPERATION
- TROUBLESHOOTING GUIDE
- TEST PROCEDURES
- [1] Procedure A: MAGNETRON ASSEMBLY TEST
- [2] Procedure B: POWER TRANSFORMER TEST
- [3] Procedure C: HIGH VOLTAGE RECTIFIER TEST
- [4] Procedure D: HIGH VOLTAGE CAPACITOR TEST
- [5] Procedure E: THERMAL CUT OUT TEST
- [6] Procedure F: SECONDARY INTERLOCK SWITCH TEST
- [7] Procedure F: PRIMARY INTERLOCK SYSTEM TEST
- [8] Procedure G: MONITOR SWITCH TEST
- [9] Procedure H: BLOWN MINITOR FUSE TEST
- [10] Procedure I: NOISE FILTER TEST
- [11] Procedure J: CONTROL PANEL ASSEMBLY TEST
- [12] Procedure L: RELAY TEST
- [13] Procedure M: FOIL PATTERN ON THE PRINTED WIRING BOARD TEST
- TOUCH CONTROL PANEL ASSEMBLY
- PRECAUTIONS FOR USING LEAD-FREE SOLDER
- COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
- [1] WARNING
- [2] OUTER CASE REMOVAL
- [3] POWER TRANSFORMER REMOVAL
- [4] HIGH VOLTAGE RECTIFIER ASSEMBLY AND HIGH VOLTAGE CAPACITOR REMOVAL
- [5] MAGNETRON REMOVAL
- [6] CONTROL PANEL ASSEMBLY REMOVAL
- [7] OVEN LAMP AND LAMP SOCKET REMOVAL
- [8] POSITIVE LOCK CONNECTOR (NO-CASE TYPE) REMOVAL
- [9] ANTENNA MOTOR REMOVAL
- [10] COOLING FAN MOTOR REMOVAL
- [11] POWER SUPPLY CORD REPLACEMENT
- [12] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH REMOVAL
- [13] DOOR SENSING SWITCH/SECONDARY INTERLOCK SWITCH AND MONITOR SWITCH ADJUSTMENT
- [14] DOOR PARTS REMOVAL
- [15] ANTENNA MOTOR SHAFT REPLACEMENT
- [16] INSTALLATION OF CERAMIC SHELF
- CIRCUIT DIAGRAMS
- Parts List
R21LCF
8 – 2
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
NOTE: Be sure to use an ohmmeter that will supply a forward bias voltage of more than 6.3 volts.
[4] Procedure D: HIGH VOLTAGE CAPACITOR TEST
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. 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 termi-
nals 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 an
open circuit once the capacitor is charged. If the above is not the case, check the capacitor with an ohmmeter to see if it is shorted between either
of the terminals and case. If it is shorted, replace the capacitor.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
[5] Procedure E: THERMAL CUT OUT TEST
1. THERMAL CUT OUT 125°C (OVEN)
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. A continuity check across the thermal cut-out terminals should indicate a closed circuit unless the temperature of the thermal cut-out reaches
approximately 257°F(125°C). An open thermal cut-out indicates overheating of the oven, exchange the thermal cut-out and check inside of oven
cavity and for improper setting of cooking time or operation of control unit. Check for restricted air flow through the vent holes of the oven cavity,
especially the cooling fan and air guide.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
2. THERMAL CUT OUT 145°C (MAGNETRON)
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. A continuity check across the thermal cut-out terminals should indicate a closed circuit. If the temperature of the magnetron reaches approximately
293°F(145°C), the thermal cut-out opens. An open thermal cutout indicates overheating of the magnetron. Check for restricted air flow to the mag-
netron, especially the cooling fan air guide.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).
7. Reconnect the power supply cord after the outer case is installed.
8. Run the oven and check all functions.
CAUTION: IF THE THERMAL CUT-OUT INDICATES AN OPEN CIRCUIT AT ROOM TEMPERATURE,
REPLACE THERMAL CUT-OUT.
[6] Procedure F: SECONDARY INTERLOCK SWITCH TEST
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. Isolate the switch and connect the ohmmeter to the common (COM.) and normally open (NO) terminal of the switch. The meter should indicate an
open circuit with the door open and a closed circuit with the door closed. If improper operation is indicated, replace the secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reinstall the outer case (cabinet).