What Classic Computer are All About - A Lovers

From: jpero_at_mail.cgo.wave.ca <(jpero_at_mail.cgo.wave.ca)>
Date: Mon Jul 14 21:25:51 1997

TJPlajer, Is this name you would preferred to called by?... :)

Whew, not meant to be long! :-(!) Or consider as a mini tutor in
 shallow depth?

Ok, that kind of heat you have is bad for any hard drives health
so we are too!
Number one: bearing will wear out rapidly by hotter
lube rapid breakdown. There's lot of forces on those little steel
balls at 3600rpm and up. The new Cheeth series are being spun
10,000 rpm. Whew. Number two: heads/platters stickum is more likely.
Number three: no longer properly aligned with both data/sector
ID...more problems by thermal expansion results in data loss/
read/write errors.

Occsionally blow dust ST225's series out and related that uses
similar design that allow airflow through the drive and board
with air hose when bezel is off.
Other way to clean dust in there is
bit risky becasue of that reddish flex data cable for heads is
diffcult to work /w and tears easily when board/3 screws are removed.
Get them installed visibly with own bezel that has air grilles. The
idea is you WANT the circuit board and that two motors per drive
cooled and whole drive as well instead of allowing heat to migrate
though the pack. Easier on bearing lives by mounting ST225 right
side up this way in a pc tower or suitable desktop case so you can
see the bezels. Perferably keep case covers closed up with two or
three fans blowing out back.

All hd's like to be handled and mounted gently to finger
tight with screwdriver on very short 3 screws, any bumps or bangs
does bad business to both bearings and dings the platters by heads,
that's true. Opened them up and saw hard-to-see 4 pits in retangular
pattern matching size of head corners caused by simple act of
screwdriver slip or 1inch drop/jars. But note, smacking the
stuck drives in rotation plane with bare hands to unstick is ok.
Sometimes and not seen the problem because it is minor but in long
run no. Ideally, low level formatted in its final position because
mounting hardware does warps the drive, yes it's true! And do it
again bi-yearly. Yes, a pain but best way to assure reliable data.
This process is a must with any stepper type drives but those that
uses voice coil does not require this fussy work, once formatted
depending on type of drive technolgoy, it's good for ever.

Those newer 3.5 ones does not cares how it is positioned but they
love being cooler so make sure airflow is there across them.
And they do not need the LLF in IDE/SCSI 3.5" and smaller drives
because it's already embedded at factory.
Dusting is limited to outside casing and logic board only because the
air flow is not possible between them. Cooling them all around
through length-wise if mounted with platter pack up.

Reasons to be so reglious about cooling and such...

Lot of stickums caused by
many things: Drives was allowed to run hot too long that coating
softens up that protects the magnetic material that assists the lube
process between head and platters during rest/spin up/down. Gets
softer and more smoother that it gets simply stuck as heads gets worn
smoother. Happens to many hds that was power cycled too often like 5
to 6 times a day even once day if you want hds to really last then I
have few tips:

Keep them happy by cooling them, handling gently/screws tightened
properly and asolutely no too long screws ever, those regular pc
screw is too long! Lots of hds were ruined by this and I have lots
of hds to show this damges. And keep power cycles to a minium when

Remember the infamous stuck drives in Mac SE and mac classics? I
think Mac blamed on Quantum and pulled at it for freebie recall for
lube problem where I see this way: overheating and running upside
down, lots of power cycles.

Side note: those ST225's uses aluminum platters physically coated
with mixture of magetic iron rust powder (opaqe orange colored) and
epoxy which gives greenish tinge. Then spun them to even up the
mixture and polished then lubing/protective coatings are applied.
Then they're graded for quality based on defects and density. No
longer (?) done now, all drives uses spluttered or plated platters
for its greater density and harder surface. They looked transpantent
(sp?) and reddish, shades of grey or clear. IBM just got past the
1gb per inch sq recently.

Jason D.

> >
> Hello there, I run a fileserver that has 2 ST-225 20 meg drives, and 1 NEC
> 420 meg IDE drive, this system runs 24/7, and has been running for 2 months
> continuous now. My question is what is the life expectancy of these drives,
> it is often said that the ST-225 series are not reliable, however they
> continue to run strong. also these things run so hot that you can fry an egg
> on it! :)
Received on Mon Jul 14 1997 - 21:25:51 BST

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