TB 9-4931-501-24
(4) If TI does not display two rows of zeros located in middle of top and bottom
graticule divisions, with 4 zeros in each row with no overlap, perform b (1) below.
(5) If the first and last zero of both rows are not within the TI graticule area,
perform b (2) below.
(6) If zeros are not complete or have over scanning, (over scanning causes a bright
dot where traces overlap) perform b (3) below.
(7) Set TI POWER switch to off and install Q1040 (fig. 5).
b. Adjustments
(1) Adjust R135 VERT CENTER (fig. 4) to position the bottom row of zeros to the
middle of the TI screen bottom graticule division. Adjust R1118 VERTICAL SPACING (fig.
5) to position the top row of zeros to the middle of the TI screen top graticule division. Due
zero location is obtained.
(2) Adjust R1110 HORIZONTAL POSITIONING (fig. 5) until first and last zero of
both rows arc within TI graticule.
(3) Adjust R1006 CHARACTER SCAN (fig. 5) for fully scanned zeros without over
scanning. Turn TI POWER switch to off, and install transistor Q1040.
21. Power Supply
NOTE
Do not perform power supply checks if all other parameters are
within tolerance.
a. Performance Check
(1) Install vertical amplifier in TI left compartment and time base in right
compartment. Pull TI POWER switch to on.
(2) Connect multimeter between test point -30 V (fig. 2) and chassis ground.
(3) If multimeter does not indicate between -29.925 and -30.075 V dc, perform b (1) below.
(4) Connect multimeter between test point +30 V (fig. 2) and chassis ground.
(5) If multimeter does not indicate between +29.925 and +30.075 V dc, perform b (2) below.
(6) Connect multimeter between voltage test points listed in table 4 and chassis
ground. Multimeter indications should be within limits specified in table 4.
Table 4. Power Supply Check
Test instrument voltage
test points
Multimeter indications (V dc)
Min
Max
-15 V
-14.85
-15.15
+5 V
+4.9
+5.1
+15 V
+14.85
+15.15
+200
+180
+220
