Seagate Cheetah ST173404FC, Product Manual

Page: 25 / 80

Cheetah 73FC Product Manual, Rev. C 15
Failure rate is calculated as follows:
• No system-induced failures counted
• Based on 1,200,000 MTBF and 720 POH per month
• Month 1’s rate includes a 300 PPM installation failure
5.2.3 Preventive maintenance
No routine scheduled preventive maintenance is required.
5.2.4 Service life
The drive has a useful service life of five years. Depot repair or replacement of major parts is permitted during
the lifetime.
5.2.5 Service philosophy
Special equipment is required to repair the drive HDA. To achieve the above service life, repairs must be per-
formed only at a properly equipped and staffed Seagate service and repair facility. Troubleshooting and repair
of PCBs in the field is not recommended because of the extensive diagnostic equipment required for effective
servicing. There are not spare parts available for this drive. The drive warranty is voided if the HDA is opened.
5.2.6 Service tools
No special tools are required for site installation or recommended for site maintenance. Refer to Section 5.2.5.
The depot repair philosophy of the drive precludes the necessity for special tools. Field repair of the drive is not
practical because users cannot purchase individual parts for the drive.
5.2.7 Hot plugging the drive
Inserting and removing the drive on the FC-AL will interrupt loop operation. The interruption occurs when the
receiver of the next device in the loop must synchronize to a different input signal. FC error detection mecha-
nisms, character sync, running disparity, word sync, and CRC are able to detect any error. Recovery is initiated
based on the type of error.
The disc drive defaults to the FC-AL Monitoring state, Pass-through state, when it is powered-on by switching
the power or hot plugged. The control line to an optional port bypass circuit (external to the drive), defaults to
the Enable Bypass state. If the bypass circuit is present, the next device in the loop will continue to receive the
output of the previous device to the newly inserted device. If the bypass circuit is not present, loop operation is
temporarily disrupted until the next device starts receiving the output from the newly inserted device and
regains synchronization to the new input.
The Pass-through state is disabled while the drive performs self test of the FC interface. The control line for an
external port bypass circuit remains in the Enable Bypass state while self test is running. If the bypass circuit is
present, loop operation may continue. If the bypass circuit is not present, loop operation will be halted while the
self test of the FC interface runs.
When the self test completes successfully, the control line to the bypass circuit is disabled and the drive enters
the FC-AL Initializing state. The receiver on the next device in the loop must synchronize to output of the newly
inserted drive.
If the self-test fails, the control line to the bypass circuit remains in the Enable Bypass state.
Note. It is the responsibility of the systems integrator to assure that no temperature, energy, voltage hazard,
or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge the static
electricity from the drive carrier prior to inserting it into the system.
Caution. The drive motor must come to a complete stop prior to changing the plane of operation. This time is
required to insure data integrity.
5.2.8 S.M.A.R.T.
S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended
to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a
failure to allow you to back up the data before an actual failure occurs.