Communications/Serial I/Otroubleshooting Guide - IBM 5100 Maintenance Information Manual

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COMMUNICATIONS/SERIAL I/O
TROUBLESHOOTING GUIDE
Use the following chart as a guide when troubleshooting
communications or serial I/O problems:
Run MOl 820; the communications/serial I/O
diagnostic MOl 820 tests the communications
and serial I/O hardware (B2 card, internal
cables, and external cables). If you suspect
the internal cables (cables from Z1 socket to
the serial I/O communications connector -
see the IBM Maintenance Information Manual),
you can jumper the following signals at the Z1
socket and run MOl 820:
Data terminal ready to data set ready
Request to send to clear to send
Transmitted data to received data
If the problem is intermittent, run MOl 820
several times.
DID MOl 820 RUN ERROR FREE?
Y N
Correct the problem indicated by MOl
820 and rerun MOl 820. If the diagnostic
runs error free, retry the user's job.
DOES THE USER'S JOB STILL FAI
L?
F
Good]
Go to entry 002.
002
Run the 5100 diagnostics. Because the communi-
cations and serial I/O features use existing ROS
microprograms and microprograms in read/write
storage, you should run the 5100 diagnostics to
eliminate possible problems in these areas.
DID THE 5100 DIAGNOSTICS RUN ERROR
FREE?
II
A B
A B
Y N
Correct the problem indicated by the
5100 diagnostics and rerun the user's
job. If you are unable to correct the
problem indicated by the 5100 diag-
nostics, use existing support procedures.
DOES THE USER'S JOB STILL FAIL?
Y N
I -
Good!
Go back to entry 002.
ARE YOU USING THE COMMUNICATIONS
FEATURE?
Y N
- The 5100 appears to be functioning
normally. Check to make sure that the
correct serial I/O cable is connected to
the I/O device and that the user speci-
field the correct device characteristics.
(See the IBM 5100 Serial I
/0
Adapter
Feature User's Manual.)
IS THE 5100 USING SWITCHED LINES?
Y N
Use the 5100 communications diagnostic
buffer to verify that the data is being
transmitted and received by the 5100
correctly. If the user's job still fails,
have the user contact the telephone
company and request a line test. If the
job still fails, use existing support proce-
dures.
If you dial the remote system again (two or
three times if necessary and wait 15 minutes
between dialing), you might establish a
different route on the communications net-
work. This procedure could bypass possible
network problems.
DOES THE USER'S JOB STILL FAIL?
Y N
C
If redialing corrected the problem, there
are possible problems with the com-
munications network. If the problem
persists, have the user contact the tele-
phone company.
Diagnostic Aids 3-13