If the attached device is an external device, do the
following before exchanging any parts:
Ensure that the Fibre Channel cable is correctly
connected to the ports.
Clean the Fibre Channel connectors.
If there is a switch or hub attached, verify that it is
operational.
If there is a gateway device attached, refer to the
gateway device service documentation for additional problem
analysis procedures.
refer to the tape device service documentation for
additional problem analysis procedures.
If the attached tape device is owned by a Virtual I/O Server partition
refer to Troubleshooting the Virtual I/O Server to determine the parts to
replace.