On Jan 7, 2017, at 3:42 AM, Pete Turnbull <pete at
On 07/01/2017 04:08, Robert Armstrong w#rote:
Koning <paulkoning at comcast.net> wrote:
one would think unplugging the power to the head actuator coils ...
One might think that, and that plan works for an RK05, but an RL02 is
smarter. Unless the heads go on cylinder within a few seconds of the head
load signal, the drive logic just faults and spins down again. Not very
useful... What's needed is a way to stall or fake out the drive startup
state machine logic.
I haven't done this for a while, but I think it might work if you also disable the SK
TO (Seek Timeout) signal on the main logic board, and maybe also POS SIG (Position
There are several setup and adjustment procedures that require one to move the heads by
hand, including right back onto the loading ramp. You'd do this with the cover open,
the logic board swung up and resting on its clip at the back of the drive, and with the
amplifier box turned to a vertical position sitting on its right-hand supports. The
procedures require the above signals to be disabled, and the servo drive (the single
inline connector under the amplifier box) to be disconnected. However, they all start by
pressing LOAD and allowing the heads to load at least as far as the loading area at the
outside edge of the disk before disconnecting the servo drive; I can't remember if the
heads actually go beyond that into the area where the data tracks are.
How you disable the signals depends on the version of the main logic board - there are
three different types, all described in the pocket service guide.
What is the best way to approach evaluating old RL02 Packs for cleaning? Does anyone have
experience opening up all the little plastic tabs on the covers?
I have a large stash of RL02?s that I had planned to backup. I was planning on just
doing a visual inspection on each before loading.
The only disassembly information I have found uses the proverbial hammer -