Lorlin Impact Test System Disk...

Sun Mar 6 16:04:00 CST 2011

OK. <blush>  I totally misread the original posting.  I thought the
discussion was about the RL02 drive and not the packs.  Apologies.

I'd love to hear how to take the packs apart and clean them...

Chris

On Sunday (03/06/2011 at 04:01PM -0600), Chris Elmquist wrote:
> On Sunday (03/06/2011 at 06:06PM +0000), Tony Duell wrote:
> > > 
> > > I recently picked up a RL02 pack from a recycler. After doing my usual 
> > > tear-down and clean process, I tested the pack on my 11/34C. It was 100% 
> >   ^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > What do you do? I know the stanadard procedure for RK05 packs, but what 
> > do you dismantle, and how do you clean, the RL's?
> 
> What a great topic... as I have been doing this exact effort for the
> past several weeks.  I have completely cleaned and brought back online
> two RL02 and a third is just entering the process.
> 
> Before I ever try to spin one up, I take the front panel off and remove
> the black pre-filter.  It is guaranteed to be disintegrating and turning
> into a fine black powder.  Exactly the kind of thing you don't want
> sucked into the drive.
> 
> I vacuum out entire front area behind the front panel and the backside
> of the panel itself.
> 
> I then take off the top covers and vacuum out the well where the pack
> sits and wipe the entire area down with a damp cloth.  Clean out ALL
> the junk...  cob webs, hairs, there will surely be a lot of junk in there.
> 
> Then I clean out the rear near the fan.  The fan blades will be loaded
> up with dust and I take off the grill and wipe those down with a Swiffer
> duster cloth as well as vacuum the whole fan assembly.
> 
> Then there is the issue of the "absolute filter" which is the roughly
> 3" x 9" HEPA-like filter accessible from the front.  I was fortunate
> to have one of these that was nearly new but others have been polluted
> by the disintegrating black foam pre-filter.  I am currently looking at
> one that is completely black on the intake side-- totally loaded up with
> the black carbon-like dust that the pre-filter turns into.  Not cool.
> 
> I was just about to post to the list asking if there is a source for these
> absolute filters still (which I doubt) or if anyone has a process for
> rebuilding them?  I've already stripped the filter element out of one and
> so I have an empty frame and am then considering modifying a HEPA filter
> for a room air cleaner or other appliance that uses a HEPA filter module.
> I will have to cut the filter to size and then glue it into the frame
> (similar to how these originals were made) using an elastomeric caulk
> or similar.  But-- is there a better way??
> 
> After dust and dirt cleaning...  then I clean the heads.  I very carefully
> use a cotton swap soaked in isopropyl alchohol...  91%...  drug store
> stuff... and rub it between the lower and upper head, sort of twirling
> it back and forth which removes the junk on the head pretty easily.
> I do this several times until the cotton swap comes out clean.
> 
> At this point, I am brave enough to try to spin the drive up.  I will
> take a known good not not precious pack and put it in the drive.  You
> of course have to have a controller connected to the drive and powered
> on so that the drive gets clock over the interface.  At this point you
> should have the fault light out and the load light lit.  You can press
> load and hear the drive spin up.  Hopefully.  I have one drive that will
> spin up, attempt to load the heads and then immediately fault.  After
> several experiments trying to get this drive to load the heads so that I
> could do some of the alignment procedures, I found that it was actually
> crashing the head into the media and I wrecked that pack.  That drive is
> now a parts donor.  I don't know exactly the failure mode but I suspect
> that the spindle is no longer aligned with the heads... due to some
> abuse like the thing being dropped.  Dunno for sure.
> 
> If you get to this point and the drive spins up and doesn't crash the
> heads then you can try to read the pack using one of the diags in XXDP2.5.
> I use ZRLMB1 which will read the entire pack and report the bad sectors
> found.  On one of my drives I had consistent failures at cylinder 490
> and beyond...  which after performing the read amplifier gain adjustment
> procedure found here,
> 
> http://bitsavers.org/pdf/dec/disc/rl01_rl02/EK-RL122-TM-001_techAug82.pdf
> 
> the problem went away.  I set the gain just slightly hotter than they spec
> on the theory that many of these packs are old now and probably produce
> a weaker signal than originally designed.  I repeat the test across a
> selection of packs to get the average signal level too since I don't
> have a "standard" test pack (saw one on eBay for $1000 the other day!!)
> 
> So, I have had good luck with 2 out of 3 RL02 so far.  These filters
> might be an interesting challenge but I don't think insurmountable.
> 
> Chris
> 
> -- 
> Chris Elmquist
> 

-- 
Chris Elmquist