IBM 3279 2A Maintenance Information page 35

3279 MIM
Chapter 2. Maintenance Aids 2-14
The positions and their uses are listed below. Note
that every jumper position is activated when
grounded. A recommended ground pin is listed.
Name
Force White
Color Balance Bars
Reverse Video
CE Jumper
Pen Detect Lines
Storage Power
Force Characters
Disable Skip
Force Green
Force Blue
Force Red
Pin Ground
C2W07' C2W28
C2W09" C2W28
D2Y02' D2Z04
or
E2Z04
D2Y09" D2Y08
D2YlO' D2Y08
B2B08 B2D08
C2G06 D2108
C2J04 D2J08
C2S11 C2U08
C2S12 C2U08
C2U11 C2U08
Use/Description
All characters on the screen become white.
Good test of convergence over whole
screen, used to set up static convergence
(at screen center).
A number of colored bars, 2 characters
high, are displayed (must be characters
on screen). Color balance.
All characters are reversed. Used to
check purity.
When the Normal/Test switch is set to the
Test position, this jumper allows entry
directly to Test Mode 3 without resetting
the refresh buffer. Nulls display,
attributes are blank, and red and white
are interchanged.
])isplays selector pen detect lines.
Removes power from storage to force a
convergence check. Used in setting up
convergence.
Easy method of filling screen with
characters when online to check overall
convergence.
Inter-row skip (Mod 2 only) is disabled.
Separator line moves up. Used when
adjusting image height.
Green video is forced permanently on.
Used to check green video amplifier and
gun.
Blue video is forced permanently on. Used
to check blue video amplifier and gun.
Red video is forced permanently on. Used
to check red video amplifier and gun.
"See Figures 1-6 and 6-3 for top card connector pin numbering.