1 Sep
2020
1 Sep
'20
9:19 a.m.
I've been trying to read data from some ~2000 era DLT III cartridges
that were written on a TZ87.
The first one read OK. But the second one failed and it seems that the
leader was torn off. I tried a new drive and a second cartridge has
failed the same way (the leader was there, now it's not).
My immediate problem is that I now have two drives (a TZ88 and a TZ870
that fail POST (all LEDs blink). I guess I need to open them up, fish
out the stray leader and fix them up somehow. Does anyone have any
experience of doing this?
My second problem is that I'd quite like to stop this from happening
again. I'm guessing that it happened because the cartridge mechanism was
jammed. I've just played around with a TK50-K cartridge and if I jam the
two release mechanisms (using the "nose" of two pliers), open the "tape
hatch" and gently pull the tape, it moves. Then I can "rewind" it and
it's back to the way it was. I'm wondering whether this is safe to do on
the DLT III tapes I still want to recover? Is it likely to at least tell
me which tapes are likely to fail and which might load properly?
My third problem i that I have two cartridges without a leader. Is this
something that can be rectified?
Thanks for any useful information.
Antonio
--
Antonio Carlini
antonio at acarlini.com
1 Sep
1 Sep
3:15 p.m.
What brand tape?
I?ve seen this done by a tech on a DLT7000 drive, maybe on a DLT4000, I think they?re
basically the same. I seem to remember the tech used a 9-Volt batter to rewind a stuck
tape. The leaders as I recall are very similar for TK50, TK70, and DLTIII.
Zane
On Sep 1, 2020, at 9:19 AM, Antonio Carlini via cctalk
<cctalk at classiccmp.org> wrote:
I've been trying to read data from some ~2000 era DLT III cartridges that were
written on a TZ87.
The first one read OK. But the second one failed and it seems that the leader was torn
off. I tried a new drive and a second cartridge has failed the same way (the leader was
there, now it's not).
My immediate problem is that I now have two drives (a TZ88 and a TZ870 that fail POST
(all LEDs blink). I guess I need to open them up, fish out the stray leader and fix them
up somehow. Does anyone have any experience of doing this?
My second problem is that I'd quite like to stop this from happening again. I'm
guessing that it happened because the cartridge mechanism was jammed. I've just played
around with a TK50-K cartridge and if I jam the two release mechanisms (using the
"nose" of two pliers), open the "tape hatch" and gently pull the tape,
it moves. Then I can "rewind" it and it's back to the way it was. I'm
wondering whether this is safe to do on the DLT III tapes I still want to recover? Is it
likely to at least tell me which tapes are likely to fail and which might load properly?
My third problem i that I have two cartridges without a leader. Is this something that
can be rectified?
Thanks for any useful information.
Antonio
--
Antonio Carlini
antonio at acarlini.com
2 Sep
2 Sep
3:11 a.m.
On 01/09/2020 23:15, Zane Healy wrote:
What brand tape?
I?ve seen this done by a tech on a DLT7000 drive, maybe on a DLT4000, I think they?re
basically the same. I seem to remember the tech used a 9-Volt batter to rewind a stuck
tape. The leaders as I recall are very similar for TK50, TK70, and DLTIII.
Zane
The torn tapes were both DEC "digital DLT CompacTape III".
I should be clearer about what I think I see. When you flick open the
back of the cartridge you should see the reel of tape and a "hole" or
loop at the end of the reel. On the torn tapes that part was missing.
One of the tapes showed clear signs of "something got pulled and
stretched until it ripped". The other was less clear, and in fact I
guess it is possible that the loop has simply been wound too far in.
I've freed the cartridge that was trapped in the TZ88. To do that I used
a screwdriver to turn the screw at the bottom of the drive (directly
under where you would imagine the centre of the inserted cartridge to
be) anticlockwise until I could see the cartridge tape pulled back into
the cartridge. Then I gently pulled out the lever on the RHS (as you
look from the front). There's a relatively large cylinder there, so it
should be obvious where that is. That TZ88 still fails POST.
Neither that TZ88 nor the TZ87 that I've opened up show any sign of
having the "small amount of tape" inside (that seems to be called the
leader). Basically this stuff:
https://www.ebay.co.uk/itm/2-x-DLT7000-DLT8000-tape-leader-70-28824-01/1143…
That's also not present in another DLT III drive that I have (and
haven't ever tried to use before) that also fails POST.
So I'm rather confused about what's happened. More importantly, I don't
know how to fix the drives I do have.
Antonio
--
Antonio Carlini
antonio at acarlini.com
7 Sep
7 Sep
9:50 a.m.
On 02/09/2020 11:11, Antonio Carlini wrote:
So I'm rather confused about what's happened. More importantly, I
don't know how to fix the drives I do have.
I thought I should follow up with further information, so as not to
pollute the archives with mis-information.
The one tape unit that I've never used does indeed have a missing leader.
As for the others, they had all snapped the tape (from the cartridge)
quite some way into the tape. So the leader was attached to the tape,
which then surrounded it on the rear spool. I missed that because I
didn't know what I was looking for. Once I realised what had happened I
gently started to unwind the rear spool enough that I could grab the
tape and then I basically pulled it all through (many metres of it)
until I reached the tape leader. The tape was discarded and the leader
reattached to the hook. That itself proved to be a bit fiddly the first
time I did it. I found that to get the drive to POST properly I had to
manually rotate the rear spool just enough to have the tape leader pull
back gently on the hook.
I also had a stuck tape. That required me to use the screw underneath
the centre of the inserted cartridge to rewind the tape back into the
cartridge. Once I'd rewound all of it the tape leader came into view. It
then detached from the tape. I don't remember if I had to do that
manually or not. Similarly I may have reattached it to the hook
manually. There's a lever to the side of the cartridge that you gently
move to allow the tape to be released by lifting the normal handle.
Antonio
--
Antonio Carlini
antonio at acarlini.com
2140
days inactive
2146
days old
3 comments
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