Dead RF31 DSSI Disk.. final Question..

Holm Tiffe holm at
Tue May 12 07:33:00 CDT 2015

Johnny Billquist wrote:

> On 2015-05-12 11:55, Holm Tiffe wrote:
> >Ok, the disk passed the tests with ok.
> Excellent.
> >I've tried to boot something from DIA0 DIA1 and DIA2..nosurchfile so the
> >disks seems to be empty.
> Oh Well...
> >Now I think about a reformat of the drives, but there is no such procedure.
> >There is an erase program that should rewrite eachs sector with several
> >patterns. I'll think that it will do the job.
> >Does an format programm exists "in the field"  or is something like thisi
> >proprietary to DEC?
> Why would you want to reformat the drives?
> That said, I would expect such a utility to exist in the firmware of the 
> drive.
> But normally, since these drives remap bad sectors automatically, you 
> should normally just go on using them, and everything is ok.
> 	Johnny

The exerciser showed some correctable soft errors, wich is pretty much
normal I think. Reformating the drive should simply "freshen up" the data
tracks but erase should do the same in this regard.
Since the distks aren't containing anything interresting, it would be the
right time now to do a reformat.
I think the head assembly has an voice coil engine anyways, so servo tracks
are needed to do the positioning. It is clear that they aren't affected from
a reformat...

I've changed some Nippon Chemicon electrolytics from the PSU now. All
330µF 25V Caps are bad, an 1000µF 25V too, where other Caps from the same
company are still ok. I've changed the 330µ Caps against some good Rubycons
470µ 25V from which I have "masses".
The construktor of that H7874 Supply is an dump asshole, no one should ever
construct switching PSU's in a way that it makes it impossible to desolder
broken electrolytic Caps! One module with 2 x 330µF Caps is build this way!
I had to pull of that bad caps, ..brown residues from the electrolyte below
them on the pcb. Cleaned the PCB with alcohol and soldered the new caps from
above, briged them with an 1206 X7R each.
Will test the PSU now...

Machine is working now as expected. Currently it is "erasing" the Disk0..
53 Minutes...


      Technik Service u. Handel Tiffe,, Holm Tiffe, 
     Freiberger Straße 42, 09600 Oberschöna, USt-Id: DE253710583, info at, Fax +49 3731 74200, Mobil: 0172 8790 741

More information about the cctech mailing list