Test Procedures And Troubleshooting - Sanyo EMO-SRT1(NX) Service Manual

6. TEST PROCEDURES AND TROUBLESHOOTING

-DISCONNECT THE POWER SUPPLY CORD FROM THE WALL
OUTLET WHENEVER REMOVING THE CABINET FROM THE UNIT.
PROCEED WITH TESTS ONLY AFTER DISCHARGING THE HIGH
VOLTAGE CAPACITORS AND REMOVING THE LEAD WIRES ON
THE PRIMARY WINDING OF THE HIGH VOLTAGE TRANSFORM-
ERS FOR LOWER AND UPPER MAGNETRONS.
(SEE FIGURE 3)
A. TEST PROCEDURES
COMPONENT
MAGNETRON
HIGH-VOLTAGE
TRANSFORMER
CAUTION
CHECKOUT PROCEDURE
1) Check for resistance: Across the filament ter-
minal of the magnetron with an ohm - meter
on Rx1 scale.
2) Check for resistance: Between each filament
terminal of the magnetron and the chassis
ground with an ohm-meter on highest scale.
1) Measure the resistance:
With an ohm-meter on R x1 scale.
a. Primary winding;
b. Filament winding;
c. Secondary winding;
2) Measure the resistance:
with an ohm-meter on highest scale.
a. Primary winding to ground;
b. Filament winding to ground;
PRIMARY
WINDINGS
RESULT
Normal reading:
Less than 1 ohm.
Figure 4
Normal reading:
Infinite ohms.
Figure 5
Normal reading:
Approximately 2.0 ohms
Less than 1 ohm.
Approximately 137 ohms
Normal reading:
Infinite ohms.
Infinite ohms.
Figure 6
Note: Remove varnish of measured point.
- 4 -
Secondary
Windings
Filament
Windings
Figure 3