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From: dp@JASPER.PALLADIAN.COM.UUCP
Newsgroups: mod.computers.vax
Subject: glue on the disks revisited...
Message-ID: <870127134727.6.DP@BANFF.PALLADIAN.COM>
Date: Tue, 27-Jan-87 13:47:00 EST
Article-I.D.: BANFF.870127134727.6.DP
Posted: Tue Jan 27 13:47:00 1987
Date-Received: Thu, 29-Jan-87 03:32:46 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Reply-To: Jeffrey Del Papa <DP%JASPER@LIVE-OAK.LCS.MIT.EDU>
Organization: The ARPA Internet
Lines: 15
Approved: info-vax@sri-kl.arpa


    > Early production of these drives had a design fault which allowed contaminants
    > to build up on the heads. This does not crash the HDA but does reach a point
    > where data can no longer be read or written with any reliability. Apparently
    > spinning the drive down temporarily cures the problem by scraping the crud
    > off the heads onto the landing zones!
    >
    > Apparently production shipped after mid August 86 does not have this problem,
    > and SI UK are arranging to swap all earlier HDAs with customers regardless of
    > whether there are problems.

some vintages of RA-81 have a similar problem. after ~1.5 years the glue holding the
paper absolute filter elements in place would de-compose and so would go your heads.

<dp>