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137
KEYBOARD SCAN CODE MINI MAP
• Use this figure to locate an open or grounded scan
code line.
• For Mini MAP example, see
Troubleshooting Aids
(212).
Conditions after Power-On
• The scan code lines are valid after a key is pressed.
Service Aids
• All scan code lines switch Up and Down when a
keyboard key is pressed. A'1' is displayed in the
scan code field on the display screen when a line
is active.
Tools
Connect the CE probe as follows:
• +lead-1-G-D03
• -lead-1-G-D08
• Ground-1-B-D08
Display Screen
Status switch at the
Test position; Keyboard
key pressed.
Scan Code
01234567
1-24
• Use the Shift key to test the' -break code' line. The
break code position in the displayed field is normally
'0'. The position changes to ' l' only after the Shift
key is pressed and released.
b
• The display station will not be damaged if
powered-on after the keyboard cable is
disconnected.
Planar
Board
I
Interposer I
Internal
I
I
I
Keyboard
I
I
I
Cable
I
I
Connector B
I
13
I
Keyboard
Signal
Cable
I I
~I
-1-
-1-
-I-i::
0
rt1
~
I
J~~
Iii
1
25
I
"
±-:::::
I ::
--~-
. .....
::::;:-t-t!tiJJ:c::::?,~
B02
Code
Keyboard Logic
Printed Circuit
Board
002
-1~71~ T~~
14
I
I
B02
I
I
-==::::::I:::-~
Clean both sides
I
002
B02
I
I
I
I
I
I
Access
I
I
~~
,
-Break Code Bit 0
I
1-B-B12
8
B12
-Scan Code Bit 1
1-B-B05
3
B05
-Scan Code Bit 2'
1-B-006
16
006
-Scan Code Bit 31
1-B·013
22
013
-Scan Code Bit 41
1-B-B08
5
BOB
-Scan Code Bit 5
1-B-809
6
BOO
-Scan Code Bit 61
1-B-810
7
Bl0
-Scan Code Bit 7
-t
1-B-B13
9
t
B;3
of the pad
printed circuit
board connector
contacts (130).
--D
+
5V
I:
I
I
I
I~
~~--~»~--------------~»~------~----~~~
1
I
I
I
Driver
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