Vector 4 - Page 138

VECTOR 4
TECHNICAL INFORMATION
SECTION II - ADJUST CRT
Summary: The following section describes the required protocol used
in adjusting the focus, vertical and horizontal linearity, brightness,
and contrast for the CRT used in the Vector 4 SBC. Fo
rinformation on filling the screen with characters used in each
adjustment, refer to III 4.3, Sereen Test.
2.1 Introduction
While reading this section refer to the following exhibits:
Exhibit III-1: Video Board Component Locations (Shows location of Screen
Adjustment POTSs).
Exhibit III-2: Yoke Diagram (shows Centering Magnet Adjustments).
- CAUTION
DO NOT TOUCH ELECTRICAL TERMINALS ON CRT OR YOKE. CRT USES
EXTREMELY HIGH VOLTAGES.
To adjust the screen, it is necessary to follow an established protoecol. This
protocol is required because the screen adjustments have inter-relating
funcetions. For instance, adjusting the Vertical Linearity can affect the
adjustment of the Vertical Size.
2.2 Screen Adjustment Protocol
1. Turn your computer system on. and rotate the contrast control fully
clockwise., If banner doesn't appear, refer to PART V (Troubleshooting
Guide) of this manual for troubleshooting procedures.
2. Rotate the contrast button counter-clockwise until you have a completely
~ black screen. Locate the POT (VR102) on the Video Board which adjusts
the brightness level. Turn this adjustment (use a small slotted
non-conductive screwdriver) until a faint raster appears on the screen
(white zig-zag lines) and then back-off the adjustment until the raster
disappears. NOTE: The brightness control adjusts the brightness level of
the entire screen,
09-01-82 7200-0001 I 2-1