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R-630A (W)
F-630A {IN}
R-630A (B)
'TEST PROCEDURES
PROCEDURE
LETTER
COMPONENT TEST
c
HIGH VOLTAGE RECTIFIER ASSEMBLY TEST
HIGH VOLTAGE RECTIFIER TEST
CARRY OUT 3D CHECKS.
isolate the high voltage rectifier assembly from the HV circuit. The high voltage rectifier can be tested
using an ohmmeter set to its highest range. Connect the ohmmeter across the terminal B+C of the high
voltage rectifier and note the reading obtained. Reverse the meter leads and note this second reading.
The normal resistance is infinite in one direction and more than 100 kQ in the other direction.
ASYMMETRIC RECTIFIER TEST
ASYMMETRIC
RECTIFIER
CARRY
OUT 3D CHECKS.
C/
HIGH VOLTAGE
RECTIFIER
Isolate the high voltage rectifier assembly from the HV circuit. The asymmetric can be tested using an
ohmmeter set to its highest range across the terminals A+B of the asymmetric rectifier and note the
reading obtained. Reverse the meter leads and note this second reading. If an open circuitis indicated
in both direction then the asymmetric rectifier is good. If an asymmetric rectifier is shorted in either
direction, then the asymmetric rectifier is probably faulty and must be replaced with high voltage
rectifier. When the asymmetric rectifier is defective, check whether magnetron, high voltage rectifier,
high voltage wire or filament winding of the high voltage transformer is shorted.
CARRY OUT 4R CHECKS.
NOTE: FOR MEASUREMENT OF THE RESISTANCE OF THE RECTIFIER, THE BATTERIES OF
THE
MEASURING
INSTRUMENT
MUST
HAVE A VOLTAGE
AT LEAST 6 VOLTS,
BECAUSE
OTHERWISE
AN INFINITE RESISTANCE
MIGHT
BE SHOWN
IN BOTH
DIRECTIONS.
D
HIGH VOLTAGE CAPACITOR TEST
CARRY OUT 3D CHECKS
A. Isolate the high voltage capacitor from the circuit.
B. Continuity check must be carried out with measuring instrument which is set to the highest
resistance range.
C. Anormal capacitor shows continuity for a short time (kick) and then a resistance of about 10MQ
after it has been charged.
D. A short-circuited capacitor shows continuity all the time.
E. An open capacitor constantly shows a resistance about 10 MQ because of its internal 10MQ
resistance.
F. When the internal wire is opened in the high voltage capacitor shows an infinite resistance.
G. The resistance across all the terminals and the chassis must be infinite when the capacitor is
normal.
If incorrect reading are obtained, the high voltage capacitor must be replaced.
CARRY OUT 4R CHECKS.
E
SWITCH TEST
CARRY OUT 3D CHECKS.
{solate the switch to be tested and using an ohmmeter check between the terminals as described in
the following table.
Table: Terminal Connection of Switch
E
COM;
Common terminal,
|__ Plunger Operation |
COM to NO
COM to NC
| NO;
Normally open terminal
|__Released
|
Oc.
S.C.
| NC;
Normally close terminal
[__Depressed
|
S.C.
0.C.
| S.C.;
Short circuit
0.C.;
Open circuit
{f incorrect readings are obtained, make the necessary switch adjustment or replace the switch.
CARRY OUT 4R CHECKS.
14
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