20 Sep
2011
20 Sep
'11
2:34 p.m.
On Tue, 20 Sep 2011, Paul Anderson wrote:
Is the little red maintence switch in the right
position? Was the
Yes, that switch simply disables the positioner current. I have it
disabled for the moment so that I can move the head assembly by hand and
observe the count pulses on the scope.
drive working earlier and just stopped? The quarterly
PM usually helps
find this type of problem. Where are you located?
Yes, the drive was working just fine. I think this is an electronics fault
on said card. Whatever I do I can observe changes on the DIFF outputs from
the ROM (outputs M0 to M4) but not on output M5. And the problem is that I
don't know when this output should go low.
I think I'll have to borrow another M7681 (and M7702 for reference) next
week from the spares of our museum (BTW I'm in Stuttgart, Germany).
Christian