Chapter 2. Maintenance Aids; Maintenance Plan; General Failure Index; Maps - IBM 3279 2A Maintenance Information

Chapter 2. Maintenance Aids
1.1 Maintenance Plan
The maintenance plan for the 3279 assumes the use
of:
1. Problem determination procedures (performed by
the customer using the Problem Determination
Guide, which is located under keyboard
handrest).
2. The General Failure Index (GFI) (see MAP
QOOO)
for simple symptoms.
3. The Maintenance Analysis Procedures (MAPs)
(referred to in section 2.3) which comprise Part
2 of this manual.
4. Intensity override (section 2.4).
5. Offline test modes (section 2.5).
6. Online tests (section 2.6).
7. Adjustment procedures (see Chapter 5).
8. FRU removal and replacement (see Chapter 4).
FRU locations can be found in the Parts
Catalog at the back of this manual.
DANGER
Do .."
Iltmltpt
to ...-.It% FR
Us "".,
ptJW#"
OIImM
It. lfItIdti,..
f -
1.1 General Failure Index
This section has been moved to MAP 0000.
1.3 MAPs
This section also has been moved to MAP 0000.
1.4 Intensity Override
To engage intensity override, turn and hold the
brightness control fully counterclockwise. Intensity
override turns on the red, green, and blue
electron-guns at maximum brightness.
3279 M1M
When the Normal/Test switch
is
set to Test, Ihe
three rasters will be unconverged (see Figure 2-1)
unless the Test Mode 3 jumper (D2Y08 to D2Y09)
is installed. Test mode checks analog and
associated circuits.
When the Normal/Test switch is set to Normal and
the 3279 is connected to an active control unit, the
red. green, and blue rasters should be converged.
Skip and display geometry can be inspected.
1.S Test Modes (Offline)
Note: When the display station is offline. the
convergence correction circuits are no/ active. This
will be obvious when more than one color is
displayed.
2.5.1 Test Mode 1: Patterll
1. Set the Dualcase/Monocase (A,a/ A) switch to
A,a.
2. Set the Normal/Test switch to Normal and back
to Test. The Test Mode 1 pattern is displayed.
3. Verify operation of Test Mode 1 by checking
the displayed pattern carefully against the
pattern shown in Figure 2-2. If the test fails,
read MAP 0000 page 2 and then go to MAP
0100, Entry Point BB.
Chapter 2. Maintenance Aids 2-1