Spinning up RL02 w/o head load ? (was Cleaning RK05 packs)

Jerry Weiss jsw at ieee.org
Sat Jan 7 10:44:06 CST 2017

> On Jan 7, 2017, at 3:42 AM, Pete Turnbull <pete at dunnington.plus.com> wrote:
> On 07/01/2017 04:08, Robert Armstrong w#rote:
>>> Paul 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 Signal).
> 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.
> -- 
> Pete
> Pete Turnbull

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  - http://williambader.com/museum/vax/43rl02topremoval.jpg <http://williambader.com/museum/vax/43rl02topremoval.jpg>


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