[Info-vax] DAT drive misreads write protect tab

[Rich Jordan]

On Oct 10, 8:56 am, koeh... at eisner.nospam.encompasserve.org (Bob
Koehler) wrote:
> In article <22c23be9-d161-478c-a0ee-a2f3a70fe... at o8g2000yqh.googlegroups.com>, Rich Jordan <jor... at ccs4vms.com> writes:
>
>
>
> > This is a home hobby site with zero budget and I'm just trying to help
> > them out.  Thanks for any info.  Suggestions to replace hardware would
> > not be helpful at the moment (though down the road they hope to
> > inherit a DLT IV drive and tapes).  They just need to keep their
> > backups going for now.
>
>    IMHO, I'd disassemble it and clean it.  There's a good chance of some
>    fuzz.  There may be a micro switch that has dirty contacts.  My
>    favorite fix for that is to clean the contacts and coat them with a
>    layer of ordinary solder.
>
>    And if none of that helps, then you probably have a weak electronic
>    component somewhere.  Not likely meant to be serviced, but an
>    electronics hobbyist might have a go at it.

Thanks all.
     I looked at a TLZ07 here and it is a small spring loaded plastic
rod that sticks up; when the tape is loaded it hits the hole in the
bottom of the cartridge.  If write enabled it is blocked, if write
protected it can slide up into the cavity; the visible white tab over
the side hole is for human consumption only apparently.

     Given that (and the high likelihood a TLZ10 is the same) then the
switch itself is probably malfing, not just a physical jam which would
tend to default to a write-enabled state instead of write protected.

The only expectation they had was if it was sticking or (if optical)
dirty they might be able to do something, but that apparently isn't
the case so replacement is in order.