IBM 300 Service Manual page 75

Modem Answer
The modem is busy
The modem does not answer
The modem answer
007
– Disconnect the modem's telecommunication cable from the public switched
network plug.
Is the modem's telephone number still busy?
Yes No
008
– Reconnect the modem to the public switched network.
– Switch the modem power off, then power on.
– From a close telephone, call the modem.
Is the modem's telephone number still busy?
Yes No
009
The problem is solved. Ask the remote operator to re-start his call from
the remote NAS.
010
The modem is defective. Exchange it (see "Modem Exchange Procedure" on
page 4-14).
011
The probable cause of the problem is the telephone line.
012
– Switch the modem power off, then power on.
– From a close telephone, call the modem.
Does the modem answer?
Yes No
013
– Disconnect the modem's telecommunication cable from the public
switched network plug.
– Connect a telephone in place of the modem to the public switched
network.
– From a close telephone, call the modem.
Chapter 4. Nways Switch Administration Station Problem Determination
MAP 0410 (continued)
Action
Go to Step 007.
Go to Step 012.
Go to Step 017 on page 4-10.
4-9