Dissecting a TZ30 drive

From: Clint Wolff <vaxman_at_uswest.net>
Date: Sat Dec 9 11:37:32 2000

On 8 Dec 2000, Rodrigo Ventura wrote:

> >>>>> "Chuck" == Chuck McManis <cmcmanis_at_mcmanis.com> writes:
>
> Chuck> I have on my desk a TZ30 (half height TK50 drive) and it
> Chuck> has a tape inside of it. Powering it up and pressing unload
> Chuck> starts a rewind and then it gives up (all lights
> Chuck> flash). I'm guessing the tape presense sensor is dirty or
> Chuck> otherwise disabled but to get to it I really would like to
> Chuck> remove the existing tape. Unfortuately I cannot find how to
> Chuck> manually "unlock" the drive. Clues anyone?

You need remove the cover from the take up reel, and see if the tape
is still hooked on the leader. If the tape is completly rewound and
unhooked, there is a small selenoid on the lower right side (looking
at the front) that needs to be pulled out to unlock the tape. You
should be able to operate the handle then.

> I extracted a TZ30 from a "storage expansion" box that used to
> be connected to a alpha station. The drive is SCSI so that it was
> trivial to use it in my PC.
>
> The load system seems extremly unreliable to me: any small
> failure when loading/unloading the tape might easly require
> disassemble it.
>

The load system is fairly reliable, with a failure rate of < 1 out of
1000 (I actually measured this on the TK50/TK70 about 10 years ago)...
If you load a backup tape every day, this is about 1 failure every
2.5 years.

A more common failure I saw was the tab on the end of the leader
breaking off. I finally got the (3rd party) field service guy to
leave a couple replacement leaders, and I fixed them myself...

It's my understanding the Quantum DLT (Quantum bought the DEC disk
group, and got the tape group thrown in for free) uses the same
loader mechanism still. Rumor has it they are redesigning it for
the next generation (Super DLT?)...

clint
Received on Sat Dec 09 2000 - 11:37:32 GMT