8 Mar
2020
8 Mar
'20
2:12 p.m.
On Mon, Feb 10, 2020 at 6:16 PM Fred Cisin via cctalk <cctalk at classiccmp.org>
wrote:
On Fri, 7 Feb 2020, Carlos E Murillo-Sanchez via
cctalk wrote:
Sorry for not replying earlier, your message made it to the spam folder.
The return is more violent than the usual return. I put a piece of paper
between the arm stop and the arm, and this did not modify the behavior. I
am now inclined to think that it is failing to find the servo data.
carlos.
system originally came with an RD53 that has sat
elsewhere for 25
years. It
passed a read test in 2005. So I tried to see if
I could read it and
maybe
image it now, but no go. The disk spins up,
initiates a seek (the arm is
not
stuck in a gooey stop pad; I've read that
this is a common failure
mechanism
for Micropolis 1325's; I opened it and saw
the arm move) but then the
arm
returns violently (clacking) to the rest
position; it does this a number
of
times (two to four, usually) and then it spins
down. Applied voltages
and
currents remain ok as this happens.
If nobody speaks up who actually know anything about them, . . .
Q: Is the return to the reset position more violent than the usual return?
If it is not different, then consider the possibility of something not
related to positioner, such as: seek to track, try to READ, FAIL, reset,
REPEAT. In which case, it could be anything that caused the read to fail,
such as head problems, failing to find the servo data, . . .