IBM 5280 Manual page 206

y
9
045
COMMUNICATION MAP
38LS XMIT/RECV CHECK
PAGE 10 OF 20
- Disconnect 'Telephone Line l'
and 'Telephone Line 2' wires
FROM THE WALL MOUNTED CONNECTOR.
Set the dB meter to the '600
ohm' pos i t i on.
- Connect meter across 'Telephone
Line l ' and 'Telephone Line 2'
ON THE RECEIVING WALL MOUNTED
CONNECTOR.
Does the db measurement look close
to the expected value for normal
operation?
Y N
046
Have the person at the
transmitting station ensure
that his transmit dB level is
correct at the wall mounted
connector.
If his transmit level is
correct, place another call to
see
if
another connection
improves the r ece
i \lcd
dB
level.
If these were not the cause of
the Dad receive dB level
measurement, have the customer
place a call to the telephone
company.
z
MAP 3011-10
047
Power off.
Disconnect external cable from
the PTT interface.
Check for an open line or a
short to ground between TPI (MIM
827) (which is a direct line to
TBl-9) and THE END OF THE
EXTERNAL CABLE.
Check for an open line or a
short to ground between TP2 (MIM
827) (which is a direct line to
TBl-8) and THE END OF THE
EXTERNAL CABLE.
Did the cables checK out ok?
Y N
048
- ChecK the cable for open lines
or shorts to ground from the
external cable interface at
the J140 connector (MIM 869,
probe point H) to the PTT
connector.
Did the cables checK out oK?
Y N
049
Defective external cable.
050
Defective internal cable to
the World Trade line plate.
051
Defective
plate.
World Trade line
EC840874 PEC839787
Z MAP 3011-10