Cheetah 4LP FC Product Manual, Rev. A
15
plish this, a counter is incremented each time the error rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. If the counter continually increments such that it reaches the pre-
dictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter.
There is a separate Failure History Counter for each attribute.
5.3
Reliability and service
The reliability of Cheetah 4LP FC disc drives can be enhanced by ensuring that the drive receives adequate
cooling. This section provides recommended air-flow information, temperature measurements, and other infor-
mation, which you can use to enhance the service life of the drive.
5.3.1
Mean time between failure (MTBF)
The production disc drive achieves an MTBF of 1,000,000 hours when operated in an average local disc drive
ambient temperature of 86°F (30°C) or less. Short-term excursions up to the specification limits of the operat-
ing environment will not affect MTBF performance. Operating the drive at ambient temperatures above these
values may adversely affect the drive’s ability to meet specifications. See Section 6.4, “Environmental limits” on
page 18.
The following expression defines MTBF:
Estimated power-on operating hours means the estimated total power-on hours for all drives in service. Drive
failure means any stoppage or substandard performance caused by drive malfunction.
Data is calculated on a rolling-average base for a minimum period of six months.
5.3.2
Preventive maintenance
No routine scheduled preventive maintenance is required.
5.3.3
Service life
The drive has a useful service life of five years. Depot repair or replacement of major parts is permitted during
the lifetime.
5.3.4
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. The drive warranty is voided if the HDA is opened.
5.3.5
Service tools
No special tools are required for site installation or recommended for site maintenance. The depot repair phi-
losophy 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.
5.3.6
Product warranty
Beginning on the date of shipment to the customer and continuing for a period of five years, Seagate warrants
that each product (including components and subassemblies) that fails to function properly under normal use
due to defect in materials or workmanship or due to nonconformance to the applicable specifications will be
repaired or replaced, at Seagate’s option and at no charge to the customer, if returned by customer at cus-
tomer’s expense to Seagate’s designated facility in accordance with Seagate’s warranty procedure. Seagate
will pay for transporting the repair or replacement item to the customer. For more detailed warranty informa-
tion, refer to the standard terms and conditions of purchase for Seagate products on your purchase documen-
tation.
The remaining warranty for a particular drive can be determined by calling Seagate Customer Service at
1-800-468-3472. The drive serial number is required to determine remaining warranty information.
MTBF = Estimated power-on operating hours in the period
Number of drive failures in the period
