On Sat, 12 Feb 2000, Chuck McManis wrote:
> Ok, so I had an old TK50Z-GA that was marked "dead" and I ripped it apart
> and discovered a couple of blow caps on the "heater" board :-) (some
> adjunct to the PSU) replaced those and it seems to work somewhat again
> (I've not hooked it up to SCSI, just powered it up to see the drive light up)
>
The "heater" board is used to supply enough load to keep the switching
power supply happy.
> Anyway, I took my other drive that I was powering up on the bench and by
> wiggling out the TK50 connector and the power connector I can now plug this
> thing in an watch it in "real time."
>
> This has yielded a bit more information about the failure mode of the
> drive. With the cover removed I can watch what the drive is doing. This is
> what I've found out.
>
> The "hook up" leader was around the spool and out of the feed path. Now
> when powered up the drive turns the spool a bit and then starts spinning it
> making the leader thingy go whack whack whack on the edges. (DEC weed
> whacker! :-) If I re-feed the take up lead through the tape path it moves
> back and forth a bit and then stops with the red light flashing.
>
> [Note to Tim: My test tape is a scratch tape]
>
> Then I fed the tape in manually and hooked it up to the leader. Now the
> tape was taken up on the spool a bit, then it rewinds to what might be the
> load point and stops. Then the red button flashes. If I try the press and
> release a few times leaving it in the unpressed position the drive feeds
> some time then rewinds and stops just as the end of the actual tape
> (beginning of the pick up lead) reaches the capstan.
>
If the "hook up" leader is a little bit bent at the end, it will not
feed past the read head. Put a little reverse bend on it, hook it to
the tape, and make sure it slides freely.
> [Reference Picture : http://home.mcmanis.com/images/tk50-2.jpg ]
>
> In the reference picture I circled in Orange where the leader stops and in
> red where I cleaned with a q-tip. I've confirmed with my IR detector that
> the LED in the lower right side of the picture (more toward the rear) is
> emitting.
>
> So several questions come to mind. I'll pop out some of the obvious ones...
>
> 1) Does the Red Light/Button on the right hand side in the "out" position
> mean "unload" ?
Off means unlocked (you can lift the handle and remove the tape)
Off also means no power (you can't lift the handle and remove the tape)
On steady means tape loaded
Flashing means rewinding or unloading or error (Grrrr)
> 2) When does the green light come on (except on power up when it is
> unloaded.) ?
When the tape is loaded and ready
> 3) It appears that a "working" unload sequence would have the tape leader
> get sucked back
> into the tape and the 'unhooker' should engage the hook leader. Why
> would it stop
> before it got that far?
>
See above
> --Chuck
>
>
>
>
Received on Sun Feb 13 2000 - 09:46:00 GMT
