MDM Trouble Report for 2013 Sep 10

Telescope: 2.4m
Observer(s): John Thorstensen (Dartmouth)
Instrument: modspec + Templeton

Problem(s) Encountered:
When I first went to use the instrument rotator, it was after
I'd shut down and I'd forgotten to open the mirror.  The 
rotator, appropriately, refused to rotate.

But after I opened the mirror cover, it still wouldn't work -- 
the symptom was that it would  clack  when the CCW button was
pushed, but didn't move.  At first I toggled the power to
the rotator control box, but that had no effect.  Then 
I vaguely remembered Ryan Hickox having a problem like this 
that had something to do with the rotator limit switches, so I 
toggled the power and also exercised the limit switch on the
east side of the telescope by moving it back and forth, and 
the rotator then worked normally. (The rotator was at zero,
so the limit switch wasn't anywhere near engaged.  The east
rotator switch is the one that trips if the rotator goes too
far CCW.)

I'm not sure whether my abortive attempt to move the thing
caused it to go into some odd state, or whether the limit
switch was actually giving a faulty reading, or what.  I just
work here.

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Submitted on 2013 Sep 11 [6:16:12]