Input Signals; 25-Line Display Service Aids - IBM 6360 Product Support Manual

I nput Signals
The following character control
signals and
the~r
functions are listed
for reference information. They can~
not be checked. The signal ground is
used as a conductor for the return of
the power supply and logic signals.
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•
•
•
•
Video Signal. The video signal
carries the character information
to the display.
Bright Control. This signal is
not used and is grounded at the
display adapter card.
Vertical Drive. This signal con-
trols the circuit in the display
module that drives the electronic
beam from the top to the bottom of
the screen.
Horizontal Drive. This signal
controls the circuit in the dis-
play module that drives the elec-
tronics beam from the left to the
right of the screen. This signal
is also used to generate the high
voltage for the CRT.
Bypass Ground. This is a frame
ground.
25-LINE DISPLAY SERVICE AIDS
DANGER
Do not remove the display covers.
Operati og voltages up to 14,000 volts
are present inside the display. No
bleeder resistor is provided.
The 25-line display module is a field
replaceable unit (FRU) which is not
field serviceable.
The raster is a normal background
image on the display screen which is
visible when the brightness control is
turned up (clockwise) all the way (see
Figure 3-10).
A blank screen or blank area of the
screen may not be a problem in the
display module. The problem may be a
change in or a loss of the input
signals.
Note:
When a displayed character is
changed an "after image" will remain
for a short time.
Figure 3-10. Display Raster
o
o
Chapter 3. 25-Line Display 3-7