(c) Check for 30-35 VDC between termi-
nals #20 and #21 of terminal strip TB1 (5). Terminal
those listed in Table 8-2 indicate an open or shorted
#20 is positive and terminal #21 is negative.
junction within Q1, Q1 should be replaced.
(d) Rotate the shaft of the test rheostat
(8) Solder lead
of diode CR6
to printed circuit
counterclockwise to approximately eighty percent of
its maximum rotation. The voltage between terminals
#20 and #21 of TB1 (5) should now be zero.
mica insulator between Q2 and regulator housing.
(e) Rotate the shaft of the test rheostat
clockwise while observing the voltage at terminals #20
(10) If necessary, apply a small amount of heat
sink compound (P/N 13217E3704, FSCM 97403) to
and #21 of TBl (5).
transistor Q2 and housing. Secure transistor Q2 with
(f) Voltage at terminals #20 and #21
screws (2) and washers (3).
should be between 30 and 35 volts when test rheostat
(11) Make test connections.
is turned to approximately eighty percent of its clock-
wise rotation. If no voltage is present, refer to step (i).
(a) Connect a 30 ohm 120 watt resistor to
terminals #21 and #20 of terminal strip TB1 (5).
(g) If there is a delay of two seconds or
more between decreases and increases of the voltage at
terminals #20 and #21 or if voltage changes do not
(b) Obtain a 750 ohm 2 watt rheostat.
occur at the eighty percent of maximum rotation
(c) Position rheostat so that control shaft
points, adjust R6. Refer to (h) for adjustment proce-
is facing you and the three terminal lugs are facing up.
dure. If no delay is present and voltage changes occur
Connect a 12-18 AWG insulated wire to the middle
at the eighty percent rotation points, testing procedure
is completed. If no voltage change occurs, regardless of
terminal lug and another wire to the left hand terminal
the position of the test rheostat, refer to step (i).
lug of the rheostat.
(d) Attach the two rheostat leads to termi-
(h) Locate R6 on the printed circuit
nals #26 and #28 of terminal strip TB1 (5). Turn the
board. Turning the adjustment screw of R6 clockwise
will turn the voltage at terminals #20 and #21 of TB1
rheostat clockwise to its maximum rotation.
(5) on for a given setting of the test rheostat. Turning
adjustment screw counterclockwise turns the voltage
(e) Connect a 0-150 VAC, 60 HZ power
at terminals #20 and #21 off. Adjust screw as required
supply to terminals #24 and #27 of terminal strip TB1
to achieve voltage cutoff and turn on for eighty percent
of maximum rotation as described in steps (d), (e), and
(f). Troubleshooting is complete after adjustment is
(12) Perform tests.
(a) Turn on the power supply and set for
Adjustment of R6 does not cause the voltage
at terminals #20 and #21 of TB1 (5) to vary.
Either voltage will be on or voltage will be