Tony Duell wrote:
I have no
black numbers printed on the connectors - only the MX-
numbers (which are moulded), and another number (starts with a 4)
which is the same on all the connectors.
Oh dear. You've got wome wiring to trace...
Joy :)
Well, you don't need to trace out the detailed wiring, only which plug
goes to the track 0 sensor, which to the frontpanel LED, and so on.
Hmm, I
may have to take the drive carrier out again to see if I've got
one of the wires tangled. From what you're saying, one of the coloured
batch belongs on B21 (J8); and it'll be a real stretch to make it
reach at the moment.
Yes. The connector numbering is actually the same as the connectors in
a Tandon TM100, and number 21 is the psindle motor. It'll be 4 coloured
wires (2 of the motor, 2 for the tacho) that go to that component.
OK. Well, that's the drive carrier coming out again then, and both the
boards back off (damn). Are those schematics you talked about readily
available for download anywhere (ie in the public domain), or are they ones
you made yourself?
They're home-made (not suprisingly). I could probably be convinced to send
you a copy...
Now, from
your list, J13 (B12) (5-pin connection printed on the
circuit board) should have connector 12 in it - which has only 4
pins.... Is the unconnected pin on the LH or RH end?
I don't know, but I explained it last night. Sirius used several different
drive mechanisms in these machines, or at least
had the capability to do
so. The stepper motor is either 4 windings with a common connection (5
wires) or 2 separate windings (4 wires). The board can handle either
(unlike,
> BTW, the Commodore 8050 which is of course somwhat similar, in that unit,
> there are 2 different 'analogue boards' for the 2 types of stepper motor).
One thing I didn't mention. There may well be different firmware for the
2 types of drive, so don't go swapping them without checking.
Anyway. one end pin on the PCB-mounted plug is
linked to the +12V rail.
That's the one you _don't use_ if you have a 4-wire motor.
OK, so I just need to find that 12v line & avoid it - gotcha.
I mentioend that too. The +ve side of C28 is +12V. So (admittedly after
some filter compoennts) is the middle pin of the spindle motor plug.
> I'll certainly try... But I'm not
willing to re-power it until I've
> sorted the power plugs...
Err, can't you just trace the grounds, +5V,
etch on the connectors
to see what would make sense?
Yep, I guess so... Just need to dissasemble it all again. Still that's no
problem now I know how it all comes apart & goes together.
THeyr'e really easy to take apart (or at least the floppy-only model is).
You just have to _loosen_ the screws and things slide out. From what I
rememebr, the drive chassis comes out first, then the PSU.
-tony