Flashing LED on old Quantum HDD PCB

I can hope that it's something fixable, if I can just find a table
which explains the code.

If you disconnect one of the RAM buffer pins, does the LED pattern
change? Doing so should result in a Sector Buffer Error (error code
03h).

Not sure where I would do that. I haven't disassembled the drive and
don't have a full technical manual for it, and I'm not sure where I
would be able to disconnect (and then later reconnect) a single pin on
a tiny SMD.

Should the flash pattern be interpreted as hex code 8A ? Do you have
something which lists these codes, or a link to something which does? I
found some information by Googling, but nothing about error codes from
the LED.

If I can't find an explanation of the flash code, I'll try the rapping
technique.

In article <LvKwAA.Hy6_at_freebie.onetel.net.uk>,
Windmill <spam-no-spam_at_Onetel.net.uk.invalid> wrote:
I can hope that it's something fixable, if I can just find a table
which explains the code.

In the older days, I had a nice big ST506 MFM shoebox sized 5.25" full
height drive. It used to fail to spin up with a blink code.

Reason: one lousy transistor that was responsible for lifting the
"brakes" solenoid off the motor, used to go pop. Never did find out why.
Just replace and continue

On Fri, 2 Dec 2011 13:26:36 GMT, spam-no-spam_at_Onetel.net.uk.invalid
(Windmill) put finger to keyboard and composed:

If I can't find an explanation of the flash code, I'll try the rapping
technique.

If the drive has a stiction fault, then you should see pulses at the
motor windings as the motor controller attempts to kickstart the
drive. I believe this is called "spin buzz".

Alternatively, there will probably be a current sense resistor, or an
array of parallel connected sense resistors, to sense the motor
current. You could measure the voltage at this point. Note that there
will also be a current sense resistor for the voice coil.

FWIW, here is my database of motor controller IC datasheets:
http://www.users.on.net/~fzabkar/HDD/HDD_Motor_Control.html

I don't know if this tutorial will be of any help to you ...
http://www.users.on.net/~fzabkar/HDD/Tutorial_SP0411N.html

In article <LvIuB5.HnK_at_freebie.onetel.net.uk>, spam-no-
spam_at_Onetel.net.uk.invalid says...
I have an old 5.25" Quantum Bigfoot CY6.4 hard drive which I want to
use in an old PC.

It was working some months ago when I hooked it up to a USB adaptor on
a Ubuntu PC and backed up its contents.

But now it isn't recognized by the OS (various old Linux and new Ubuntu
Linux versions), neither on the old PC nor on the USB adaptor.

'dmesg' shows info for a different drive (which works), but nothing for
the Quantum drive.

There's a little green SMD LED on the PCB which is steadily lit at
first (and the BIOS displays its capacity, C/H/S, etc. so can obviously
read the drive) but which then begins to flash repeatedly in a pattern
of 8 flashes - short pause - 10 flashes.

Not sure if that could be something built into the firmware, or some
pattern of repeated access attempts by the kernel.

I've tried it jumpered as master and as slave, and with an old 40
conductor ribbon cable and a new 80 conductor cable, on its own and
with a CDROM drive. But nothing works.

I'm puzzled. Is the LED a disk activity light? There's something about
one I/O line being sometimes shared as a 'slave select' and a 'disk
activity' line, but I can't see what that would have to do with the
problem.

I have a very vague and possibly unreliable memory of having to tinker
a bit, or do something special, when the drive was new, but no clear
recollection.

Going to see if I can find any HD diagnostic program which might report
something, but meanwhile, does anyone know what the flash pattern
indicates?



Yup sounds like a stuck drive. Those bigfoots did that a lot, as did the
earlier Seagates.

As mentioned by another, just rap the drive on it's side, and it should
let go. Be aware however, that the stuck head may pull off the magnetic
material when it breaks loose. Normally we did this as a last ditch
effort to get the data off of the drive before tossing it out.

In article <LvKw0C.Ho7_at_freebie.onetel.net.uk>,
Windmill <spam-no-spam_at_Onetel.net.uk.invalid> wrote:

Thank you for that. I had already backed up the drive (though I wish I
had also backed up all the partition tables, or done an image backup of
the entire drive) so I have the data.
If I can't find an explanation of the flash code, I'll try the rapping
technique.

An approach I find more effective in dealing with "stiction" problems
in older hard drives (and somewhat gentler on the drive):

- Set it down gently, flat, on a smooth table-top.

- Grasp it on both longer sides (i.e. across its short axis) with
one hand.

- Rotate it sharply, without lifting it from the table, by "snapping"
your wrist.

Often, the inertia of the platters will "break free" whatever is stuck
(head-to-platter or shaft-to-bearings).

I agree with others, though... a drive which has stictioned itself
once is probably not to be trusted. If you get get it to spin up,
make another set of backups immediately. If you want to keep using
it, leave it spinning... it may stick again if it's powered down for
some time.

You mean tap the drive into the side of a trash can.

Oddly I have a 12GB bigfoot on my desk, I use to keep a pile of papers
from blowing away.

Had a drive once I had to use longer cables and park it on the desk so I
could clout it with a screwdriver handle immediately after pressing the on
button.

Took a fair bit of skip raiding to find a replacement that started without
'help'.

Used to work on ancient mainframes long ago ...

If I can just find my glasses.