Dead RF31 DSSI Disk..

Holm Tiffe holm at
Mon May 11 10:23:12 CDT 2015

Holm Tiffe wrote:

> Hi all,
> I've got a VAX4000/300 lately to save it from the dumpster.
> I've cleaned the machine an powered up. It taked several tries
> to get the PSU working stable, it shut off itself the first ~10 tries
> but works stable now.
> (Yes I know all about forming electrolytic caps but have my own point of
> view regarding supplying under voltage to switching psu's)
> The machine is doing the Post until the final displayed letter "3" in
> the LED Display.
> The machine is equipped with 64MB RAM, an KA670, and on the QBUS with the
> KZQSA DSSI and the TK70 Controllers and additional am CMD CQD200.
> Disks are 2x RF31 one RF71 and a TK70.
> I currently have no console device connected to the machine, must crimp a
> MMJ cable first..
> The Problem ist, that one of the RF31 Disks doesnt go to ready and the
> Fault LED lights up.
> What can I do to further investigate the Drive fault?
> Are DSSI disks starting up themselves after applying Power and ACLO or
> has the controller to supply a spindle start command?
> re those disks known to have sticking heads sometimes?
> I would do some test on the drive w/o the machine since I don't have any
> test equipment in the room where the machine now is..
> Any hints?
> If anyone has a spare RF31 or RF71 (or similar) to sell or additional MS670
> memory for an hobbyist price, please mail me. I'm in germany, europe.
> Regards,
> Holm

..have done some experiments with the disk. I've connected it to its front
paneel and an PC Powersupply, +12,+5 and GND.
After Power up the Fault, ithe Run and the write Protect LED are lit.
If I connect ACLO shortly to +5V, the Drive spins up, all 3 LEDs are going
off and then write protect reappears (Button pressed).
If I press the RUN/READY button I hear the drive step slowly for approx 15
seconds, then the red Fault LED reapears and the drive stops stepping.

If I start the Drive with the RUN/READY Button pressed, the drive starts
that slow stepping and then the Fault light goes on too. The drive keeps
spinning in both cases.

Is that behavior normal? I've never had todo with DSSI Drives before.

What could be the fault on this drive, does it just need a reformat?
Is there a sort of a mainenace programm to do this, hopefully standalone
from a Tape or ibetter from the KZQSA ROM so?



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