dp@JASPER.PALLADIAN.COM.UUCP (01/27/87)
> 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>