RL drive lubrication
ard at p850ug1.demon.co.uk
Thu Apr 13 13:28:26 CDT 2006
> Tony Duell wrote:
> > I could tell you many stories of times when I've spent hours looking for
> > a fault only to find I've not plugged it into the mains, or there's no
> > fuse in the plug, or....
> Well, as it turns out, I *was* partially brainless with this episode
I know that feeling _very_ well :-)
> > The pocket service guide (is that on Bitsavers?) is probably the best
> > reference to tell the boards apart. I have that that booklet too, and can
> > tell you what to look for if you have problems.
> Yes, I do have a copy of the pocket service guide, thanks to bitsavers.
It's a suprisingly uesful manual. Yes, you need the printset as well,
but the pocket guide does have some stuff in it that's not obvious from
looking at the drive.
> Interestingly, Drive 0's head carriage *did indeed* have some fair
> resistance to motion when I first tried to move it. As I exercised it a
> few times it loosened up and moved pretty well after about a dozen full
> travel cycles. I actually believe this was a problem. If the heads
FWIW, I've never tried to dismantle and reassemble an RL positioner, so I
don't know how hard it would be, and even if it's possible (all the DEC
manuals seem to suggest replacing it as a unit, alas). Maybe I should
sometime (I've got a MINC with a pair of RL01s that's not doing anything
much, I wouldn't worry too much if I couldn't reassemble it).
> couldn't budge, certainly the drive wouldn't come READY. I guess the
> lubrication on the rails or the pull cable cylinder (or whatever it is
IIRC, there's a permanent magnet DC motor that turns that cable drum.
Maybe its bearings were gummed up or something.
> Drive 0, having been reconnected to the 11/23, still didn't show READY,
> but I *was* able to talk to it. I even went so far as to image a whole
> disk cartridge to my PC without difficulty. Checking the READY
> indicator bulb, I discovered the bulb was burned out. Duh! (I told you
> I was partially brainless during this whole episode.) However, after
> replacing the bulb with a new one (I have a supply for just this
> purpose), I still don't get a READY light. More to look into, but the
> drive now actually works!
Well, there can't be much wrong with it, then. I am pretty sure the fact
that it works means that the internal ready signal is going active. So
it's either the lamp driver chip (on the logic board I think), the cable,
lamp holder, soemthiog like that.
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