Seagate ST157N - 2.7.1 Enabling the Offline Selftest Routines

2.7.1 Enabling the Offllne Selftest Routines
To enable the test, short the following pins to ground at the SCSI con-
nector: 2, 12, 16 and 32.
The seHtest Is In three parts. They wlll cycle In order until power or a
grounding jumper
Is removed, or untll 1 O complete passes. The LED wlll
remain on during the test and wlll tum off If an error Is detected or a
jumper
Is removed. The LED wlll flash continuously If 1 O passes are com-
pleted without error.
Part One: All sectors In the user data area are read starting with logical
block
zero.
Part Two: This Is a butterfly seek/read test. Starting at the center of the
user data
tracks, the unit wlll seek outward and Inward by Increments
until
the llmlts of the user data tracks are reached. A one-track read Is
performed to verify position.
Part Three: This part performs a write/read compare on all sectors of
the diagnostic cylinders using data pattem 6DBH. The diagnostic
cylinders are located at an Inner region on each media surface. Any un-
recoverable errors will terminate the test and tum off the LED.
ST125N/138N/157N Product Manual, Rev. C 19