Chapter 5. Display Adjustments - IBM 3279 2A Maintenance Information

Chapter S. Display Adjustments
The complete adjustment procedure shown and
detailed in this chapter is sufficient to set up a
display from a totally unadjusted condition.
If only one control needs adjustment, for example
<;olor balance, go directly to the procedure in
section 5.3 for that control. Adjustment of purity or
any of the seven raster controls may disturb
convergence. :
If
the dynamic convergence has a
marginal range, readjust the static convergence.
Also, after a single FRU change, there is no need
to go through the complete procedure. The
necessary adjustments are listed below.
1.
Power Supply Card: Perform the initial checks
(section 5.1), then go to static convergence
(section 5.3.1) and work forward to make minor
adjustments.
2. Analog Card: Perform the initial checks (section
5.1), then go to coarse adjustments (section 5.2)
and work forward. Ignore Red Brightness and
Color Balance (sections 5.2.1, 5.3.6, and 5.3.7)
unless the display is too dim or too bright.
3. Logic Card B2: Perform the initial checks
(section 5.1), then adjust static convergence
(section 5.3.1) and dynamic convergence
(section 5.3.3) only.
4. Amplifier Card: Perform the initial checks
(section 5.1). Do not adjust the four controls
marked GAIN on early level cards; these are
preset during manufacture. Go to coarse
adjustments (section 5.2) and carryon to adjust
red brightness, color balance, purity, static
convergence, and dynamic convergence only.
5. Video Card: Perform the initial checks (section
5.1), then if necessary, adjust red brightness and
color balance (section 5.3.6 and 5.3.7).
6. CRT: Perform all the adjustments starting at
section 5. 1.
7. Convergence/Purity Coil Assembly: Perform the
initial checks (section 5.1), then go to coarse
adjustments (section 5.2) and carry on to adjust
purity, static
convergen~e,
and dynamic
convergence only.
3279 MIM
8. Planar Strips: Perform the initial checks
(section 5.1), then check dynamic convergence
(section 5.3.3).
Warning: Use adjusting tool, IBM Part 1864853, to
adjust potentiometers; screwdriver blades will damage
them.
ADJUSTMENT PROCEDURE
(Section 5.11
Initial Checks
(Section 5.2)
(Section 5.3.1)
(Section 5.3.2)
(Section 5.3.3)
(Section 5.3.4)
(Section 5.3.5)
(Section 5.3.6)
(Section 5.3.7)
(Section 5.3.8)
Figure 5-1. Adjustment Procedure
Chapter 5. Display Adjustments 5-1