Browse Prior Art Database

Use of Sample Margin Techniques to Isolate Component Faults To Particular Field Replaceable Units

IP.com Disclosure Number: IPCOM000119687D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 3 page(s) / 93K

Publishing Venue

IBM

Related People

Kerwin, GJ: AUTHOR

Abstract

Disclosed is technique for utilizing performance margin, derived from the sampled values of an amplitude sampling data channel, to determine the probability of a specific field replaceable unit (FRU) or combination of FRUs being responsible for a failure in a disk drive. At the heart of the technique is the analysis of the combined relative performance of each head/disk combination in order to arrive at failure types that could cause such combinations.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Use of Sample Margin Techniques to Isolate Component Faults To Particular
Field Replaceable Units

      Disclosed is technique for utilizing performance margin,
derived from the sampled values of an amplitude sampling data
channel, to determine the probability of a specific field replaceable
unit (FRU) or combination of FRUs being responsible for a failure in
a disk drive.  At the heart of the technique is the analysis of the
combined relative performance of each head/disk combination in order
to arrive at failure types that could cause such combinations.

      Fig. 1 shows a data path flow for a typical direct access
storage device (DASD).  Each head/disk combination is grouped with
others to be serviced by an arm electronics (AE) integrated circuit.
The AE chip, often in concert with one or more other AEs, conducts
the read and write signals down the flex cable to the remainder of
the file electronics.  For many small disk drives, this file
electronics is confined to one main FRU.  The file electronics
interfaces, usually with more drives, to the host CPU via a file
controller.  In the example shown in Fig. 1, the FRUs are labeled A
and B.  It is assumed that the disk enclosure (A) must be replaced as
a unit due to the need for a clean room atmosphere for disassembly.
The file electronics card (B) could be divided into several FRUs as
is the case for large disk drives.  In smaller drives, though,
integration of the electronic components to optimize the volume
allotted to these components has usually resulted in a single
assembly. This assembly contains everything outside of the disk
enclosure.

      The flow chart of...