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2. Adjust these two controls so that the raster is 1/4-
inch from the left and 3/8-inch from the right CRT
edges.
3. Turn the G2 control counterclockwise until the ras-
ter just disappears.
Horizontal Oscillator Adjustment
The horizontal oscillator control L3402 (located on the
main board) is for oscillator frequency adjustment.
1 . Disable the automatic phase control (APC) by jum-
pering
+
12 VDC to pin 27 of the sync processor
IC3401.
2.
Adjust L3402 for an oscillator frequency of 15,734
Hz.
3.
Remove the jumper from
+
12 VDC and pin 27
of IC3401.
+
95 Volt Adjustment
The
+
95 volt (9
+ )
adjustment is located on the main
board. The test point is located on the sweep board
(see Figure 4-4).
1. Connect the monitor to the AC line through an iso-
lation transformer.
2. Connect the ground lead of the voltmeter to the
hot AC ground.
3. Connect the hot lead of the voltmeter to the
+
95
volt test point.
4.
Adjust the 95-volt control for 95 volts.
Page 4-8
SWEEP ASSEMBLY ADJUSTMENTS
HIGH VOLTAGE
AND HORIZONTAL
SWEEP BOARD
+95 VOLT
TEST POINT
WIDTH
PI JUMPER
1--fl'-P2 JUMPER
Figure 4-4
WIDTH SELECTION
(,JUMPERS SHOWN IN
POSITION FOR ZENITH
COMPUTERS)
High Voltage and Sweep Board/width
Step Board Adjustments
Focus Adjustment
With a video source connected to the monitor, adjust
the focus control for the clearest (sharpest) display.
The focus control is located on the sweep board (see
Figures 1-2, 4-2, and 4-4).
Width Selection
NOTE: This selection must be made before attempting
width adjustment.
Coarse width is controlled with jumpers P1 and P2.
For Zenith computers, P1 should
be
in the upper-
vertical position and P2 should
be
in the lower-vertical
position.
With P1 and P2 in the lower-vertical position, the width
of the display is much wider than can be used on a
Zenith computer.
Servicing
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