TROUBLESHOOTING
TESTING AND ADJUSTING
POSSIBLE CAUSES
VERIFICATION PROCEDURE
(Continued)
If all checks show continuity, remove the leads from the cathode
of CR9 and from the anode of CR10. Check continuity from
spade terminal (11) to spade terminal (19). Also check continuity
between spade terminal (6) and spade terminal (8). If continuity is
shown in either test, the module (A2) has an inside short circuit.
Make a replacement of the module as necessary.
16 Regulator Module (A1) Has a
Test procedures for this component are in the section on
Defect
REGULATOR MODULE.
17. Shorted Suppression Diode
Surge suppression diode (CR7) is installed on positive heat sink
(CR7 or CR8)
(E1) and has a positive stud-type terminal. Surge suppression
diode (CR8) is installed on negative heat sink (E2) and has a
negative stud-type terminal. Disconnect (CR7 and CR8) by
removing the wire to the spade terminal of each diode. Check the
forward and reverse resistance of each diode. Typical resistance in
both directions will be 15,000 ohms or more.
NOTE: A suppression diode failure can normally be found visually
or by the odor of selinium that has become too hot.
18. Shorted Surge Suppression
Disconnect surge suppression diode (CR11) by removing wire (6)
Diode (CR11)
and both wires (19) connected to its spade terminals. Check the
resistance of (CR11) with an ohmmeter connected to the spade
terminals. Resistance must be 15,000 ohms or more.
NOTE: A failure of the suppression diode can normally be found
visually or by the odor of selinium that has become too hot.
19. Open Suppression Reactor (L1)
Disconnect suppression reactor (L1) by removing wire (26) from
terminal (26). Check continuity from wire (26), through suppression
reactor (L1) to wire (12) at suppression capacitor (C2).
Resistance is zero.
20. Open SCR Reactor (L2)
Disconnect SCR reactor (L2) by removing wire (19) from spade
terminal (19) of rectifier module (A2). Check continuity from
wire (19), through SCR reactor (L2) to wire (12) at suppression
capacitor (C2).
NOTE: Suppression reactor (L2) is several turns of wire with an
air core. Resistance is zero.
21. Shorted Suppression Capacitor
Disconnect suppression capacitor (C2) by removing wire (6) from
(C2)
the spade terminal on the capacitor. Ohmmeter scale must be on
RX1000. Check continuity of (C2) from the spade terminal from
which wire (6) was removed to the spade terminal that wires (12)
are connected. When the ohmmeter test cables are first connected
to the capacitor, a low resistance will be seen. As a charge from
the ohmmeter is put on the capacitor, there will be an increase in
resistance until a constant indication is seen.
22. Shorted RFI Capacitor (C1)
Disconnect the RFI suppression capacitor (C1) by removing both
wires (6) from the spade terminal on the capacitor. Ohmmeter
scale set to RX1000. Check continuity of the suppression
capacitor (C1) from the spade terminal from which wires (6) were
(Continued on next page)
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