[q]Re: Q950 SCSI Problems

[PeterH5322]

>I came across a similar problem fairly recently when I was in the 
>position of donating old kit to a local charity. The hard drive simply 
>seemed to have "stuck". All I did was to haul the hard drive out of the 
>box, hold it in the palm of one hand and give it a bloody good slap 
>with the other hand!

Although this problem, dubbed "sticktion" back in the Seagate ST-225 (20 
MB, 5.25 SCSI drive) days, was generally believed to be fixed by drive 
manufacturers in the 3.5" and 2.5" drives, and the last of the 5.25" 
drives, this problem occurs often with drives of any of the above sizes, 
should the drive be left unoperated for a relatively long period of time.

The proper procedure to "fix" such a drive is to apply a source of power 
to the drive, listen for the drive's so-called dc controller to attempt 
to "spool up" the drive, which attempt will initially fail, but which the 
drive will repeatedly execute until the drive becomes "unstuck". 
Application of a firm slap to the *side* of the drive will eventually 
unstick the drive. It may take three to ten, or even more such attempts 
in order to resolve the problem.

Once the drive starts to spool up, the problem is resolved.

The "root cause" is a flaw in the formulation of the lubricant which is 
applied to the substrate of the disk platters during manufacturing.

The originally formulation was OK, but the manufacturer "lost" the 
formulation and proceeded to ship a large, but unknown number of drives 
each having this flaw.

Although IBM, unlike other manufacturers, made its own substrates, it 
also suffered from these problems. IBM drives most often seen with 
"sticktion" are the 1 GB and 2 GB, 1" high drives found in the Q950, the 
WGS 95, and the 9150 (and related models).


-- 
Quadlist is sponsored by  and...

 Small Dog Electronicshttp://www.smalldog.com   | Enter To Win A |
 -- Canon PowerShot Digital Cameras start at $299   |  Free iBook!   |

  Support Low End Mac 

Quadlist info:  
  --> AOL users, remove "mailto:";
Send list messages to:  
To unsubscribe, email:  
For digest mode, email: 
Subscription questions: 
Archive: 

Using a Mac? Free email & more at Applelinks! http://www.applelinks.com

[q]Re: Q950 SCSI Problems

[David Bell]

Hi

I came across a similar problem fairly recently when I was in the 
position of donating old kit to a local charity. The hard drive simply 
seemed to have "stuck". All I did was to haul the hard drive out of the 
box, hold it in the palm of one hand and give it a bloody good slap 
with the other hand!  Heresy perhaps, but that seemed to free whatever 
might have been "stuck". No cost, and perhaps worth a go. As far as I 
know, the old 950 is going just fine for the charity folk.



David

On 15 Feb 2004, at 02:03, Andrew Witte wrote:

Hi,

I'm new to the list (although I've been browsing the archives etc. for
some time now) and am starting right off with a "PLEASE HELP"
message...
The other day I tried to boot a Quadra 950 which has been sitting
(unplugged & unused) under my desk for 2-3 years now. When I power it
up, I got the "blinking disk with question mark" icon. It boots fine
from the System 7.5 Network Access floppy and from a Norton tools
floppy (also System 7.x). However, Norton can't see either of the 2
internal hard disks on the SCSI bus. An Apple external CD-ROM drive (on
the second SCSI bus) isn't available either.
What might be causing this problem, and what might I be able to do 
about
it?

Some info that might be important:
The computer was working fine the last time it was powered up.
Mac OS 8.1 is installed on one of the internal disks.
I've tried to boot with and without external SCSI devices attached.
I've opened the case, all ribbon cables and connectors seem fine.
I've tried resetting the PRAM.
Thanks in advance for your help!

Andrew Witte

--
Quadlist is sponsored by  and...
 Small Dog Electronicshttp://www.smalldog.com   | Enter To Win A |
 -- Canon PowerShot Digital Cameras start at $299   |  Free iBook!   |
  Support Low End Mac 

Quadlist info:  
  --> AOL users, remove "mailto:";
Send list messages to:  
To unsubscribe, email:  
For digest mode, email: 
Subscription questions: 
Archive: 
Using a Mac? Free email & more at Applelinks! http://www.applelinks.com



--
Quadlist is sponsored by  and...
Small Dog Electronicshttp://www.smalldog.com   | Enter To Win A |
-- Canon PowerShot Digital Cameras start at $299   |  Free iBook!   |
 Support Low End Mac 

Quadlist info:  
 --> AOL users, remove "mailto:";
Send list messages to:  
To unsubscribe, email:  
For digest mode, email: 
Subscription questions: 
Archive: 
Using a Mac? Free email & more at Applelinks! http://www.applelinks.com