Maxtor full-height 5.25" drives of death

[Ian]

On Feb 8, 2018, at 11:03, Tom Gardner via cctalk <cctalk at classiccmp.org> wrote:
> 
> XT2190 was first produced in 3Q 1984 and last produced in 1989 which gives yours a remarkable life span and well beyond the them at most 5 year warranty.
> Be thankful they lasted this long.

Good point. 

The lisp machines I’ve been using the drives with are way past their prime too- pushing 34+ years outside of their warranty.

I think next time one fails, instead of trying to understand the problem and repair it so it can last another 30, I’ll just be thankful it lasted this long, gold scrap the boards, and build a gaming PC out of the case. 

It did, after all, have a good run. /s

I will now try, likely in vain, to put this thread back on the rails-

A colleague, offline, in the first useful and on-topic response to my query, tells me that there is an analog head preamplifier on the ribbon inside the HDA which is suspect- a drop out here can cause both the ‘missing head’ behavior, as well as the bad positioning behavior- if the head is on the servo track- common to these drives. 

This makes intuitive sense.

As there are a number of machines that *require* the ESDI Maxtor models- IBM RT, early SGI, Symbolics- in the absence of an ESDI emulator- I think repairs are a good option.

I’ll experiment on a 2190 MFM model I recently imaged that shows up with lots of errors on the same heads. It uses the same HDA as the ESDI models.

I’ll report back here, though it seems no one on the list is interested in discussion beyond anecdotes when it comes to 80s hardware.

My hope is that it simply needs the joints attaching it to the ribbon reflowed.

- I


> 
> Tom
> 
> -----Original Message-----
> From: Ian Finder [mailto:ian.finder at gmail.com] 
> Sent: Wednesday, February 07, 2018 11:36 AM
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Maxtor full-height 5.25" drives of death
> 
> XT2190s, XT1140s, some of the early ESDI disks...
> I have 6 XT2190s at home, and maybe one of the damn things works.
> 
> Does anyone out here know, beyond speculation, what some of the common failure modes of these drives are? I'm not opposed to open-HDA surgery.
> 
> And I probably won't do anything.
> But the question of WHY this line of drives in particular sucks so much has haunted me for some time...
> 
> - Ian
> 
> Honorable mention: CDC Sabre, Wren.
> 
> -- 
>   Ian Finder
>   (206) 395-MIPS
>   ian.finder at gmail.com
> 
>