ard at p850ug1.demon.co.uk
Tue Jan 17 17:13:38 CST 2006
> I will first describe the results that I saw with looking at
> the LEDs on the boards in the small rack inside the RK07 drive.
> A small LED on the outer board (M9016) is always ON.
That may be something as trivial as power...
> In the stand-by condition the UNLD HDS LED is ON.
Good. This means the drive is trying, or has, unloaded the heads (i.e.
off the disks totally)
> When I load a pack, and push the LOAD button, the LEDs
> SPEED OK and BRUSH go ON after approx 15 seconds.
The former means the spindle motor is up to speed, the latter means it's
starting the brush cycle (where it sweeps the platter with the brushes
driven by that little synchronous motor at the rear right of the pack, if
you've not been sensible enough to remove the brushes).
> A number of seconds later the LEDs BRUSH and UNLD HDS go OFF.
Right, it's finished the brush cycle, it's going to load the heads.
> At that same time the LEDs LD HDS en FWD go ON and the heads
Which is now doing. FWD means forward movement of the heads, of course.
> move toward the centre of the spindle. When the head has
> reached that position, the LEDs LD HDS and FWD go OFF, and
> RTZ and REV go ON. The head moves back, and when the heads
OK, it's doing REVerse movement to the heads to Return To Zero
(cylinder). Exactly what it should be doing.
> are on "track 0" (this is an assumption) those two LEDs go OFF
> too. Only the SPEED OK LED is still ON.
This sounds right....
> I will have to boot RT11 to tell the error message.
> AFAIK, you can not format the pack, only do an INIT.
Are you sure about that? You can't recover a bulk-erased pack because
you can't rebuild the servo surface, but this drive has a separate servo
surface so there's no good reason why you couldn't reformat the data
surfaces. I've not tried it, though.
> I did not check the cable to the controller and to the next drive,
> but I am pretty sure they are in the port A connections. As the
> second drive is OFF (and has the terminator), and the controller
> is OFF, I guess that this does not interfere with the load sequence
> getting to the READY lamp ON state.
It's been several years since I fiddled with one of thsese (too many
machines, too little time...) but something in the back of my mind says
that one of the lamps comes on when the controller accesses the drive for
the first time. It may just be the lamp in the 'A' button.
> I can see the motor that drives the spindle runs, and the belt is OK.
> It must be driving the platters, otherwise I think the SPEED OK LED
> would not turn ON.
> Indeed, there are 4 heads. The wires from one is clearly connected to a
> different board, so that must be the servo data.
> I will do your experiment, Tony.
> And no, I will not blame you if the heads crash :-)
> Good to hear that no FAULT light ON is OK.
> I can also try the second drive this weekend, but I must remove the
> brushes from that drive first. I have a third drive (!) but then
> I must move stuff around to get to it ...
I beleive you do need to keep the motor and microswitch (and the
operating cam, etc) in the drive. Just remove the brushes themselves from
the ends of the arms.
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