IBM 5280 Manual page 77

C
4
DATA ENTRY MAP
A-Al DISPLAY
PAGE
5 OF 18
003
Turn the
control panel
Brightness
until video
Control clockwise
appears, or fully
clockwise if no video.
Is the Display completely dark
(no raster)?
Y N
004
Is the Display
stable
(synchronized)?
Y N
9 6
005
Is
This checks for a vertical
sync problem.
the complete Display
moving up or down?
Y N
006
- Power problems can appear
as display problems such
as distortion, flashing,
et c.
Measure all voltages
supplied to the A-AI
card.
See MIM 463 for the
ripple voltage check.
Are the voltages correct?
Y N
007
GO TO MAP 8000,
ENTRY POINT A.
D E F G
F G
MAP 1010-5
008
Suspect a defective ground to
the Brightness Control
terminal I (MIM 217).
- - - - OR
Defective Display (MIM 181).
- - - - OR - - - - -
Defective Keyboard/Display
M
PUc a r d (A- AI) ( M 1M2 0
0 ) •
If a 'ROS Patch' cable is
connected to the card,
GO TO MAP 0600, ENTRY POINT A.
009
- Probe the display connector
P20-009, Vertical Drive'
(MIM 200, 217).
Up light: On
Down light: On
Are the lights correct?
Y N
010
Power off.
Disconnect
217) .
Power on.
A-AI-POI ( t-1It-'1
Probe A-AI-TP-13, ' - Vertical
Drive' (Mlt-l 200,217).
Up light: On
Down light: On
Are the lights correct?
Y N
6 66
H
J
K
EC840874 PEC839787
MAP 1010-5