Sponsored By:

Subject: Re: LX200 self-diagnostic test problem
From: W. Miller
Reply To: mapug@shore.net
Date: Thu Mar 14 00:13:02 1996

Albert Schuitema alberts@pi.net 13MAR wrote:
...self-diagnostic test, but fails to end it. After the 'beeb' I can hear
the DEC-motor running for a short moment, then the RA-motor is tested, but
won't stop! So the computer can't complete this self-test.
-----------------------------------------------------------------------------------
Albert,
The RA drive self test turns the worm one way then the other, for about 3 seconds
each direction, at a speed (very approx) 20x the sidereal rate. I had mine apart
this JAN and attached a piece of tape, like the hand on a clock, to the shaft
that comes out the side of the RA gear box. It could be looking for the once per
8 minute sidereal rate worm switch closure or just counting slots on the strobe
disk, I don't know. I was happy to see it behave this way after replacing the L2724
Op Amps. Before this it would either keep running in just one direction or not
at all. I saw the input signal to the L2724 was good and the output (motor
direction) bad, so I knew what had to be done.

Bill Miller, Los Gatos, CA