IBM 5280 Manual page 87

B A A
4 J L
1 1
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DATA ENTRY MAP
A-Al DISPLAY
PAGE 15 OF 18
082
Use MIM 217 to trace the
'+
Video Drive'
or grounds.
- - - - OR -
line for opens
Defective Display Unit (MIM
181).
083
084
Defective the Display unit
(MH1181).
- Probe A-A3B04~
(MIM 531).
'9 MHz clock'
Up light: On
Down light: On
Are the lights correct?
Y N
085
For the line probed in the
previous step.
Up light: Off
Down light: On
Are the lights correct?
Y N
A A
T U
086
- Defective Diskette/Main MPU
card (A-Cl) (MIM 303).
If a 'ROS Patch' cable ;s
connected to the card~
GO TO MAP 0600,
ENTRY POINT A.
A A
T U
MAP 1010-15
087
- Power off.
Set the CE meter to the RXl
scale.
- Connect the positive lead to
A-C7D04~
'9 MHz
clock'~
and
the negative lead to ground.
Is the meter reading 30 ohms or
above?
Y N
OS8
Leave the meter connected
as in the previous step.
- Use the net list (MIM 531).
Remove each card in the
net, one at a time, until
the meter reads 30 ohms or
above.
Replace the last card
removed.
If all cards in the net
have been removed and the
meter reading is still
below 30 ohms, suspect a
ground on the Logic Board.
089
Defective Diskette/Main MPU
card (A-Cl) (MII'1 303).
If a 'ROS Patch' cable ;s
connected to the card,
GO TO MAP 0600, ENTRY POINT A.
090
Probe A-A7B09, '2.25 MHz clock'
<l'lIM
531).
Up light: On
Down light: On
Are the lights correct?
Y N
1 1
6 .6
A A
V W
EC840874 PECS39787
MAP 1010-15