Mail To: Vassilis Papathanassiou <papval@otenet.gr>
Subject: Diverse stuff
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Hi Vassilis

It's been five days since I got this now, because I've been a bit busy.
Still, better late than never...


>>Well, I assumed something had come up to prolong your absence.
>>Was all of that in connection with your work ?
>>
>No, the exotic part(! Dubai-Maldives) was vacation, since my wife had those
>days off. So, the moment I returned back, we got the plane to Dubai. It was
>sudden of course, something like a 'last minute flight'!

I see.  You mentioned in an earlier mail that your wife worked for an airways
company, with some free tickets as a fringe benefit (cancellations ?).


>----- snip ----- re: the disk CRASH
>
>>Is this a SCSI or an IDE unit ?, and was it under power during this time that
>>you were gone ?
>>
>It is (was ?) a Quantum Empire 1080S (SCSI) drive, this doesn't boot from TOS
>(needs SCSI ID), but I was booting from the SyQuest.

So until the drive receives an ID command it will not respond to any command,
so how can any command be sent to it...?  Before it has an ID I mean...?
This must be something brought into the SCSI world from the PC community !
(Plug and pray ?)

It is one thing to *allow* the ID to be changed, that is flexibility,
but to *demand* it to be set up at each boot is insanity.


>----- snip ----- re: useful drive recovery info
>
>Thanks a lot for the hints, I'll check such components. For the moment the
>communication to the drive is OK, HDDRIVER reports QUANTUM EMPIRE 1080S etc

That means that the causes I suggested are not the problem, because in those
cases there can be no communication at all.


>but the drive's light stays on since it can't put the heads where it needs to
>read info (or so I think). I have 5 and 12V all over the PCBoard, but the
>four power transistors at the output to the motor(?) although correctly
>biased, they are not contacting when they should (ie I get no 12V as a
>'floating' voltage at the output). Since they seem ok I assume that they
>don't get the 'command' to power the motor and this could be due to a
>destroyed IC or a component like the ones you described.

Sounds bad, and like it will be tricky to find the real cause.


>Note also that the drive is 'shaking' three times trying to position the
>heads and then gives up.

Shaking behaviour is often the result of an imbalance between drive coils,
where some of them work while others do not (or their power transistors).



>The disk surface is spining slowly during this time
>but it definetely doesn't get the 12V to make it spin to maximum speed.
>
>I have Quantum's data sheet for the drive with the jumper locations etc but
>it isn't great help.

They seldom are.  All they are good for is to find those jumpers.  For real
troubleshooting you need a proper service manual, or at least the tech manual.
I do have some such manuals, but only for older drives like the Quantum LPS
120/240 AT and some others of similar age.

My best advice is to try to find someone else with the same type of drive,
and pay him to let you switch interface boards temporarily. This could let
you copy the contents to another disk, whereafter you switch back so each
drive has its original board again.  Another good thing about finding a
drive like that, even if he won't let you switch boards, is that you can
make measurements for comparison between the dead unit and the live one.
That can be a great help in nailing down any suspicions you have.


>The drive was unterminated since the SCSI termination
>was always (and still is) at the SyQuest EZ135.

Ok, then I don't think that that is a factor to worry about.


----- snip ----- re: crash recovery problems
>
> Any suggestions for my new SCSI drive ? (reliability and speed !)

I don't have much experience of new stuff myself, and one of my old
favourites used to be Quantum, which you are hardly keen on right now.
I also think well of Conner and Maxtor, which are old names in SCSI.
