Keyboard Cable Check Mini-Map; Conditions After Power On; Service Aids; Tools - IBM 5251 Series Maintenance Information Manual

140
KEYBOARD CABLE CHECK MINI-MAP
• Use this mini-MAP to locate an open in the cable
check lines.
• For mini-MAP example, see Troubleshooting Aids
(212).
Conditions After Power On
Both the' -cable check A' and' -cable check B' lines are
at a Down level.
Service Aids
The display station will not be damaged if it is powered
on after the keyboard cable has been disconnected.
I
Interposer
I
Planar
Board
I I
-!--I-~::
I
±-==
I ::
I
I~;
,
~ ~
-1-7,
T-~02
I
B02 002
I
B02
I
I
I
I
I I
!
I
-Cable Check A
I
1-B-B02
I
I « »
Internal
Keyboar
Cable
Tools
Connect the CE probe as follows:
• +lead-1-G-D03
• -lead-1-G-D08
• Ground-1-B-D08
13
Access
Panel
1
»
I
I
21
Keyboard
Signal
Cable
B02
B02
~
I
I
012
1-64
Keyboard Logic
Printed Circuit
Board
-I
J
'-8-012
l
K
~~----------------~~--------------~>-----~
»
).
-Cable Check B
I I
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