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Perform the steps in sequence for most effective results.
1. Turn power off.
2. Take display station offline by removing coaxial signal
cable from display station I/O jack. Jack is located at
front of display station. Front cover must be removed
for access to it.
3. Turn power on. Within 15 seconds, cursor should
appear on screen at character location
O.
No indicators
should be lighted.
4. Press
-+
(Right) key, and hold it down. Cursor should
move through each character location in the row. After
reaching last character location, cursor should appear
in first character location in second row.
5. Exercise
t
(Up),
+
(Down),
+-'
(New Line), and
+-
(Left) cursor move keys. Observe that each key
performs its operation correctly.
6. Press several alphameric keys in succession. The corres·
ponding characters should display, and cursor should
move one space as each new character appears.
7. Key in a complete row of characters. When last
character of row enters, cursor should appear in first
character position of next row.
8. Press an alphameric key. Char.acter should appear in
cursor location, and cursor should advance one space.
9. Exercise both upper and lower shift of all keys.
Observe display screen as each key is pressed, checking
that proper characters enter.
10. Exercise Typamatic function of each Typamatic key.
11. Move cursor into last row, and key in several alpha-
meric chararacters.
12. Backspace cursor near middle of group of characters
just entered.
13. Press INS MODE key. INSERT MODE indicator should
light.
14. Press Space bar enough times to cause characters at
right of cursor to move to end of row and wrap around
to first row.
15. Press RESET key. INSERT MODE indicator should go
out.
16. Delete several characters using DEL key. Character in
cursor position should disappear, and characters in
same row at right of cursor should move left one
character position each time DE L is pressed.
17. Move cursor to middle of a row of characters.
18. Press ERASE EOF key. Characters from cursor posi-
tion through last position on screen should erase, and
cursor should not move.
19. Press ERASE INPUT
key~
All characters should erase,
and cursor should move to location
O.
20. Enter several alphameric characters as in step 6.
21. If display station has the security key lock feature, turn
key off. Characters should disappear from screen,
INPUT INHIBITED should light, and cursor should
remain displayed.
22. Turn security key on. Original data should reappear on
screen, and INPUT INHIBITED should go out.
23. Press CLEAR key, then RESET key. All characters
should disappear from· screen, and cursor should
reappear in character location·
O.
24. Press Backspace key two times.
25. Press any character key. Audible alarm (feature) should
sound when key is pressed if feature is installed.
26. If an operator identification card reader is attached,
proceed to step 27. Turn power off, and reconnect
control unit signal cable if a card reader is not attached.
27. Press CLEAR key, RESET key, then enter several
alphameric characters as in step 6.
28. Return cursor to location 0 using
+-
(Left) key.
29. Read in card reader test card (PN 2143816).
30. Observe that INPUT INHIBITED indicator comes on,
cursor moves 40 spaces, and keyed-in data disappears
from screen as card passes through reader.
31. If cursor does not move 40 spaces, read-in operation
was unsuccessful.
32. Offline tests are completed. Turn power off, and
reconnect control unit signal cable.
5.1.3 Voltage Clecks
A ferroresonant transformer (ferro) with a 110V ac primary
and multiple secondary taps provides all display station
voltages. (World Trade Corporation display stations use a
ferro with a tapped primary winding.) The ferro is
protected by fuse F 1 in series with its primary winding. F 1
is located in the prime power box. Display station voltages
consist of low dc voltages, high dc voltages, and 6.3V ac
CRT filament voltage. These voltages can
be
checked at the
LV printed circuit (PC) board or at Terminal Board
1
(TB1).
Refer to the Symptom Index and Troubleshooting
Diagrams if a voltage is incorrect or is missing.
5.1.3.1
Low-Voltage DC Checks
Modell: For +8V and -12V, measure the low dc voltages at
the capacitor screws on the LV printed circuit board.
Diagram 7-9 shows the location and the polarity of the
capacitor screws. Remove the left side cover for access to
the circuit board. For +5V and +34V, measure the voltages
at the fuse holders at A/F 1-B for +5V and A/F2-B for +34V
(Diagram 7-3).
Model 2: For +8V and -12V, measure the low dc voltages
through the access holes in the shield that covers the
printed circuit board. A line with arrowheads at each end
designates the pairs of terminals associated with each
voltage. For +5V and +34V, measure the voltages at the
fuse holders at 01C/F 1-8 for +5V and 01C/F2-B for +34V
(Diagram 7-E). Diagram 7-10 illustrates the PC board shield.
Remove the front cover for access to the circuit board.
Observe the polarities of the terminals, and probe with
the correct test leads to prevent damage to the meter. The
following voltages can be measured at the PC board:
Checks, Adjustments, and Removals
5-3
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