TB 9-6625-2213-24
11. Power Supply
NOTE
Do not perform power supply checks if all other parameters are
within tolerance.
a. Performance Check
(1) Press and release LINE PUSH ON/OFF pushbutton to OFF.
(2) Remove TI top cover.
(3) Remove A26 EXTENDER (fig. 4) and A1 6 ASSY (power supply board (fig. 4)).
(4) Plug A16 ASSY into extender and then plug extender into A16 ASSY (fig. 4) slot
in chassis.
(5) Connect TI to autotransformer and adjust autotransformer for 115 V ac output.
(6) Press LINE PUSH ON/OFF pushbutton to ON.
(7) Measure dc voltage between A16C6 (located on left end of large capacitor near
bottom of board (fig. 4) and chassis ground. If multimeter does not indicate between -19.8
and -20.2 V dc, perform b (l) below.
(8) Vary autotransformer output between 105 and 125 V ac.
Multimeter will
indicate between -19.8 and -20.2 V dc.
(9) Measure ripple voltage between A16C6 (located on left end of large capacitor
near bottom of board (fig. 4)) and chassis ground. Multimeter will indicate less than 1.0 mV.
(10) Measure dc voltage between A16C3 (located on right end of large capacitor near
bottom of board (fig. 4)) and chassis ground. If multimeter does not indicate between +19.8
and +20.2 V dc, perform b (2) below.
(11) Measure ripple voltage between A16C3 (located on right end of large capacitor
near bottom of board (fig. 4)) and chassis ground. Multimeter will indicate less than 1 mV.
(12) Press and release LINE PUSH ON/OFF pushbutton to OFF.
(13) Restore all assembly boards to original positions.
b. Adjustments
(1) Adjust A16R23 (fig. 4) for a multimeter indication between -19.8 and -20.2 V dc (R).
(2) Adjust A16R11 (fig. 4) for a multimeter indication between +19.8 and +20.2 V dc (R).