Component Test Procedures - Sanyo EM-FL50N Service Manual

6. Tighten and secure the plastic bracket with
screws.
7. To be totally sure that switches are func-
tioning properly, see Primary, Secondary
Interlock Switch and Monitor Switch Test
Procedures.
DO NOT ATTEMPT TO ADJUST INTERLOCK
SWITCHES WITH OVEN ENERGIZED. IF
THIS WARNING IS NOT OBSERVED, HIGH
LEVELS OF MICROWAVE LEAKAGE MAY
BE PRESENT.
NOTE: IF THE INTERLOCKS
REPLACED, THEY
ADJUSTED. SEE
ADJUSTMENTS SECTION FOR
PROPER ADJUSTMENT PROCE-
DURE.
PRIMARY (UPPER)
SWITCH TEST
1. Disconnect power to the unit. Remove the
cabinet and discharge the capacitor.
2. With the ohmmeter set on the RX1 scale,
take continuity readings as noted below.
A) Condition: Door open
Test: Ohmmeter check from LC to MSC
indicates open circuit.
B) Condition: Door closed
Test: Ohmmeter check from LC to MSC
indicates short circuit.
3. If the switch does not operate as described
above, replace all the switches. Repeat the
above tests.
SECONDARY (LOWER) INTERLOCK
SWITCH TEST
1. Disconnect power to the unit, remove the
cabinet and discharge the capacitor.
2. With the ohmmeter set on the RX1 scale,
take continuity readings as noted below.
A) Condition: 1)Door open
Test: Ohmmeter check from SISC to
SISNO indicates open circuit.
B) Condition: Door closed
Test: Ohmmeter check from SISC to
SISNO indicates short circuit.
3. If the switch does not operate as described
above, replace all the switches. Repeat
the above tests.
WARNING:FOR CONTINUED PROTECTION
AGAINST EXCESSIVE RADIATION EMIS-
SION REPLACE ONLY WITH PARTS AS
DESCRIBED IN THE PARTS LIST
CAUTION: WHEN REPLACING
SWITCHES, USE ONLY FACTORY REPLACE-
MENT PARTS. REPLACING WITH ANY
OTHER PART WILL VOID THE WARRANTY
AND MAY CAUSE INJURY TO THE USER.
MONITOR (MIDDLE)
SAFETY SWITCH TEST
1. Disconnect power to the unit. Remove the
cabinet and discharge the capacitor.
2. With the ohmmeter set on the RX1 scale,
take continuity readings as noted below.
A) Condition: Door open
Test: Ohmmeter check from MSC to MSNC
indicates open circuit.
B) Condition: Door closed
Test: Ohmmeter check from MSC to MSNC
indicates short circuit.
3. If the switch does not operate as described
above, replace all the switches. Repeat the
above tests.

COMPONENT TEST PROCEDURES

ARE
MUST BE
INTERLOCK
INTERLOCK
HIGH VOLTAGE COMPONENT OPERA-
TIONAL TEST
In this section we have tried to lay these tests
out in a logical sequence so that you can iso-
late any suspected high voltage problem.
1. Unplug oven from its power source.
2. After removing the cabinet discharge the
capacitor by shorting the two capacitor ter-
minals together with an insulated screw-
driver.
3. Visually check the high voltage wiring for
proper connections. Refer to wiring dia-
gram for proper wiring sequence.
CAUTIONS: HIGH VOLTAGES ARE PRE-
SENT DURING THE COOK (HIGH) CYCLE,
SO EXTREME CAUTION SHOULD BE
OBSERVED. WHEN TESTS ARE COMPLETE,
ALWAYS UNPLUG THE OVEN FROM ITS
POWER SOURCE AND DISCHARGE THE
CAPACITOR.
NOTE: DO NOT TOUCH ANY OVEN COM-
THESE
PONENTS OR WIRING DURING OVEN
OPERATION.
POWER TRANSFORMER TESTS
TRANSFORMER
INTERLOCK CHECK
An operational test can be made in order to
determine whether or not primary power is
being applied to the transformer.
CAUTION: APPROXIMATELY 2070V AC IS
PRESENT AT THE HIGH VOLTAGE TERMI-
NAL OF POWER TRANSFORMER DURING
COOK CYCLE. OBSERVE CAUTION AT ALL
TIMES.
1. With the oven power cord unplugged and
2. With alligator clips, connect a meter capable
3. Plug oven in and set for regular cook opera-
FILAMENT VOLTAGE CHECK
An operational test can be made in order to
determine the amount of filament voltage pro-
duced by the power transformer.
CAUTION: APPROXIMATELY 2070 VOLTS AC
ARE PRESENT AT THE HIGH VOLTAGE TER-
MINAL OF THE POWER TRANSFORMER
DURING COOK (HIGH CYCLE). OBSERVE
CAUTION AT ALL TIMES.
1. With oven power cord unplugged and cab-
2. Remove the high voltage lead that con-
NOTE:
3. With alligator clips, connect a meter capa-
4. Apply power to the oven and put the oven
INPUT VOLTAGE
5. If a normal 2.8 to 3.75 Volts AC reading
6. If the input voltage is normal, but no fila-
5
cabinet removed, discharge the capacitor
with an insulated screwdriver.
of measuring at least 230V AC, across the
input terminals to the transformer.
230V AC
tion. If all primary circuits are functioning
properly, 230V should be applied and meas-
ured across transformer.
PRIMARY
FILAMENT WINDING
1
(CATHODE)
2
F
LOW VOLTAGE - 3.22V AC
HIGH CURRENT
FA
inet removed, discharge the capacitor with
an insulated screwdriver.
nects the capacitor to the high voltage ter-
minals.
DURING TEST OPERATION, KEEP
METER, HANDS, ETC., WELL
AWAY FROM THE HIGH VOLTAGE
TERMINALS OF THE POWER
TRANSFORMER.
ble of measuring up to 10 Volts AC across
the magnetron filament terminals.
into cook (high) cycle to get a filament volt-
age reading. A normal indication should be
approximately 2.8 to 3.75 Volts AC. Unplug
the oven before disconnecting the meter
leads.
was indicated on the meter, go to step 6.
ment voltage is present, replace the power
transformer.