[u3b.tech] Tape head alignment for 3B2's

mjm@griffin.UUCP (Mark J. Muthig @ Phoenix Telecom, Inc.) (09/30/89)

We are experiencing problems with our SCSI tape systems on our 3B2
computers (310's, 400's, 600's, 700's).  All tape drives concerned
are 60 MB SCSI drives (the 700 tape drive is 60/120 MB format).

THE PROBLEM:  Tapes which are created on different drives can not
always be read on other drives.  There does not seem to be any pattern
that we can identify, just that some fail more than others.  All the drives 
pass tape diagnostics.

THE QUESTION:  Does anyone recognize these symptoms?  Does it sound like
some type of alignment problem?  And if so, does anyone know of any
alignment tests or utilities for the 3B2 tape drives?

My guess is that the tape heads are reading and writing OK, so diagnostics
say the drives are OK.  It's just that the alignment is off on one or more 
of the drives, making tapes incompatible between tape systems.  You can 
imagine the obvious nightmare for the releasing software distribution tapes.

The drives are manufactured by Wangtek, Inc., but I do not have an
address or telephone number for them.  AT&T HOTLINE has been of
little help, offering to replace the `bad' drive, but exactly which
drive is bad, and how will they know.

Any help would be greatly appreciated.

============================================================================
Mark J. Muthig
Phoenix Telecom, Inc., 500 Helendale Road, Rochester, NY  14450
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