If the bumper is there it will be on the side wall of the HDA where the head actuator would touch when retracted. If the heads move freely you have a driver failure. the scream is the stepper motor trying to move with only one phase working. (Also a common drive failure.)
Joe > On Oct 23, 2015, at 4:26 AM, Josh Dersch <dersc...@gmail.com> wrote: > >> On 10/23/15 1:19 AM, Joseph Lang wrote: >> There is a plastic bumper in the head/disk assembly that turns to goo. >> When the head retracts it hits the bumper and gets stuck in the goo. The goo >> will eventually win. The head will no longer load. I can't say For sure this >> is your disk problem but it was a verry common Maxtor failure. > > I thought that was true for Micropolis drives (like the DEC RD53, a > Micropolis 1325/1335) -- or does the Maxtor have a rubber bumper as well? As > I said I had one open and the heads were not stuck (I could move them with my > finger -- while the drive was spinning of course :)) and I didn't notice any > goo-laden parts, but maybe I wasn't looking in the right place... > > - Josh > >> >> Joe >> >>> On Oct 23, 2015, at 3:04 AM, Josh Dersch <dersc...@gmail.com> wrote: >>> >>> Hi all -- >>> >>> I acquired a Symbolics 3640 today and it came equipped with two "large" >>> capacity Maxtor MFM drives (an XT-1140 and an XT-2190). The 1140 spins up >>> fine and we were able to image it using Dave Gesswein's MFM emulator (yay). >>> >>> The 2190 does not, and it fails in precisely the same way I've personally >>> seen three or four other Maxtor drives of the same era fail: It spins up >>> fine, but when it goes to load the heads, it sounds like the voice coil >>> positioner for the heads is "screaming" -- it emits a high-pitched, quite >>> loud whine/buzz which persists until you power the drive down. The drive >>> is unresponsive during this time. >>> >>> I'm fairly sure it's not a head crash or anything like that; having gone >>> through this a year or so ago with a similar drive that was scratch anyway, >>> I opened it up and verified that the heads weren't stuck, and I see no >>> evidence of a head crash after disassembly. >>> >>> Further, the fault does not appear to be on the logic board -- we swapped >>> in a board from a working 2190 tonight and afterwards the drive exhibited >>> the same symptoms. >>> >>> I've had this happen to other 2190s and 1140s and a few of the ESDI drives >>> in the same family, some of which were working in my possession for weeks >>> before failing -- has anyone else seen this? Any ideas? I'd kind of like >>> to recover the data off of the 2190 from the 3640... drat. >>> >>> Thanks, >>> Josh >
