IBM 5280 Manual page 220

G
3
COMMUNICATIONS MAP
CBS COUPLER
PAGE 4 OF 13
019
Do
you hear the dial tone? NOTE:
Talk/Data mode switch NOT manually
raised.
Y N
020
- Lift the talk/data mode
switch.
Do you hear the dial tone?
Y N
I
021
Power off.
- Remove the 3SLS card.
Check continuity between
A-DSD02 '+Data Modem Ready'
(MIM 867, probe point C) and
the Yellow lead AT THE
COUPLER.
I
Is cont;nu;ty
III
:22
good?
- Disconnect
cable
the internal
from the
communications MPU card at
connector A-ES-J01.
- At the
POI
connector ON
THE EXTERNAL CABLE check
continuity between POI-IS
'+Data Modem Ready'
(MIM
867, probe point E) and
the Yellow lead AT THE
COUPLER.
Is continuity good?
J
K L M
MAP 3012-4
023
- Disconnect the external
cable from the machine at
connector J140.
At the P140 connector ON
THE EXTERNAL CABLE check
continuity between P140-20
'+Data Modem Ready' (MIM
867, probe point
F)
and
the Yellow lead AT THE
COUPLER.
Is continuity good?
Y N
024
Defective external
cable.
02S
Defective internal cable.
026
Defective communications MPU
card (A-ES)(MIM 811).
I-f a 'Ros Patch'
cablp is
connected to the card,
GO TO
MAP
0600,
ENTRY POINT
A0
027
028
Defective 38LS line adapter
card (A-D7)(MIM 812).
Can calls be placed as with a
normal telephone?
Y N
Y N
029
1
3
H
J
K L M
5
The problem is in
the
telephone.
Have the ~ustomer place a call
to the telephone company.
EC840S74 PECS397S7
N
MAP 3012-4