13 Apr
2006
13 Apr
'06
11:28 a.m.
Tony Duell wrote:
I know that feeling _very_ well :-)
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 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.
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
Argh!
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.
-tony