Vax Unix tape problem

[Don Speck]

    Half a year ago, our TU77 went through the same symptoms:
errors on about every tenth tape.  Cleaning the heads thoroughly
would get it going only for another ten tapes.

    Finally one night while cleaning the heads, I got out a
mirror and flashlight to have a good look at the heads.  They
were pretty badly scored.  And no wonder:  in 4.5 years of
daily dumps, some 15,000 miles of tape had ground off most of
a millimeter.  (Magtape is kinda like a rouge polishing belt).

    I told DEC that the heads were shot, and would they please
replace them.  Instead, they went through all the adjustments,
replaced most of the boards, and had the VAX (our ARPAnet gateway)
down half the day running diagnostics.	Finally, they admitted
defeat and ordered new heads.  The drive has worked fine ever
since, and more importantly, the Field Service guy and his boss
learned to listen to me.

	Don Speck	speck at cit-vax.arpa