[sci.electronics] Cleaning a Hard Disk ??

lharris@utgpu.UUCP (12/09/87)

Hi.  
I have a ATASI hard disk drive (120 meg i think) that someone opened
because they thought it was dead.  (that is a long story - insurance paid
for the damaged drive - yes the person is a moron.)  
Anyways - from what i can gather the only problem was the brake became jammed.
I looked at the servo that controls this and freed it up.  There are no marks
on any platters and the heads move freely.  The only thing is how do i get it
dust free again.  
I have access to a laminar flow hood with a HEPA filter, 1 micron solvent filters
etc. so thats no problem.  The main question is should I rinse the whole drive
in freon (or another inert solvent) to get rid of dust and pack it up in the hood
or is it ok just to make sure the heads don't load, pack it up, power it on and
let the internal air filter clean things?
Please - any help would be very much appreciated.
Thanks
/leonard

dya@unccvax.UUCP (Edison Carter) (12/10/87)

In article <1987Dec8.161307.12488@gpu.utcs.toronto.edu>, lharris@gpu.utcs.toronto.edu (Leonard Harris) writes:
> 
> Hi.  
> I have a ATASI hard disk drive (120 meg i think) that someone opened
> because they thought it was dead.  (that is a long story - insurance paid
> on any platters and the heads move freely.  The only thing is how do i get it
> dust free again.  


   We have an employee here at DataSpan, Inc, who got really bored one
day and did the following:

   A Vertex Technology 70 mb hard drive had evidently jammed on something
(it is a voice coil actuated drive).  After removing it from our product,
and charging it off to warranty, etc. he removed the cover and evidently
got the drive mechanically OK again.

   Subsequently, he sawed off the bottom of the lid and glued a piece of
Plexiglass to it with RTV compound, reassembled the drive, and it
evidently has formatted and plays until this very day.  The room he
assembled it in is one where considerable assembly, test, and repair
of electronic equipment goes on. 

   I'd just put it under a laminar hood, see if you can knock all the
accumulated dust out of it, and reassemble the drive. Evidently, these
drives are tough.

   His experiment to reassemble the drive with a broken head failed,
though.

   There isn't a whole helluva lot you can do with it besides reassembly
and test. Now, this drive had metallic (not oxide) media, but this 
probably wouldn't matter. 

David Anthony
DataSpan, Inc

kyle@meow.UUCP (kyle) (12/15/87)

In article <856@unccvax.UUCP>, dya@unccvax.UUCP (Edison Carter) writes:
>    Subsequently, he sawed off the bottom of the lid and glued a piece of
> Plexiglass to it with RTV compound...

Why on earth would he do such a thing?  How much of the lid did he saw off?
If he was trying to make a "demonstrator" that people could watch in action
(and I'm not saying that is what he was doing), why not just replace the
WHOLE lid with a plexiglass equivilent?
-- 
		Kyle Rhorer
		meow!kyle@nuchat.UUCP

lharris@gpu.utcs.toronto.edu (Leonard Harris) (12/19/87)

Well , I managed to get the disk cleaned and dust free again ( i blew filtered
air through the unit in a HEPA filter hood, then packed it up and let it
rotate without loading the heads for an hour.) It now appears to pass its
power-on self test (it doesn't disengage the spindle and seeks tracks) but
I can't get any controller to recognized the drive.  I'm using a western digital
controller (the 3/4 board for ibm pc) and it doesn't recognize it.  The ibm says
"invalid drive c" and both the program diskmanager and the WD EPROM format can't
find the drive.  What gives ??
/leonard

krc@cs.purdue.EDU (Kenny "RoboBrother" Crudup) (12/20/87)

In article <1987Dec18.182017.340@gpu.utcs.toronto.edu>, lharris@gpu.utcs.toronto.edu (Leonard Harris) writes:

> Well , I managed to get the disk cleaned and dust free again ( i blew filtered
> air through the unit in a HEPA filter hood, then packed it up and let it
> rotate without loading the heads for an hour.)

Jeez! You musta been desperate to open up a HD! You *do* know you've violated
the warranty now!!  :-)

> It now appears to pass its
> power-on self test (it doesn't disengage the spindle and seeks tracks) but
> I can't get any controller to recognized the drive.  I'm using a western digital
> controller (the 3/4 board for ibm pc) and it doesn't recognize it.  The ibm says
> "invalid drive c" and both the program diskmanager and the WD EPROM format can't
> find the drive.  What gives ??
> /leonard

(IBM PC. My condolences :-)

If its a WD HDC in an IBM PC/XT (today is "acronym" day) you probably need to
re-low-level-format it again. The WD controllers read-out the tracks/cyls/
sectors/drive type stuff right off the HD when formatting, and if it does'nt
see this stuff it'll bitch and tell the PC.

OK. You've now tried that and it still doesnt work. What error does it give?
There is a probability if it is a large (>10 MB) disk that the HD itself can
find an internal error (not up to speed, no servo tracks) and the CPU on it
says no-go. When it gets to speed, does it do a restore? (That inital
swee-sick it makes when it moves the head in some, then out again to
track 000) Does the speed "sound" right? One thing you may want to
do is take a look at /READY (pin 34, I believe on the 34 pin conn) to
see if it is low. Just for checking, see if the edge conn's are on
right (and have no breaks in the lines) and that the select jumper
is in the right place.

I hope this helps.

-- 
Kenny "_R_o_b_o_B_r_o_t_h_e_r" Crudup		krc@arthur.cs.purdue.edu
Purdue University CS Dept.		
W. Lafayette, IN 47907			A mind IS a terrible thing to waste,
+1 317 494 7842				but I AM having fun at it!

wtm@neoucom.UUCP (Bill Mayhew) (12/22/87)

Could it be that the repaired drive being attached to the WD
controller is not a "standard" ST-506/412, but rather an ESDI, SMD,
SCSI, or whatever?  Some of the latter types still have data and
control cables that look the same as ST-506/412, thus disguising
their real identity.

--Bill