> Dear Colleagues
>
> I had given my LX200 classic a goto command. It started moving,
> and then sounded like it was getting bound and came to a halt
> before reaching the target. I could not identify any cord, etc.
> that might be binding. I powered down, then powered back up.
> The LED's on the front panel light up, and the hand controller
> lights up, but the hand controller displays "Meade" and nothing
> more. The LED's on the front panel light up about 7 bars on the
> power meter (70mA?).
More like 1A...
The bars seem to represent between about 100mA each to 150mA each. At 7
bars, something is seriously stuck, and damage may well result to the
circuitry if it is left like this for any time.

> They do increase to 8 bars if manual pressure is applied to the
> dec knob (whatever that means).
Not a lot. The Dec motor is trying to hold the position it has been
commanded to goto, and 'fights' attempts to manually move it. You can damage
the drives by doing this with any force.

> Normally, only about 3-4 bars light up when the system is not slewing.
> In any case, the system appears to halt during the boot process,
> and also appears to be drawing more than normal current. I suspect
> perhaps the RA motor is bound, but how could this be, and how can
> I unbind it (if it is the case)? The fuse appears o.k. behind the panel.
First, do not switch the scope on again, till you have found the problem.
With it switched off, move the Dec drive in both directions with the manual
knob. Does it feel smooth?. If it moves normally, you have really ruled out
the Dec system as the problem (the RA motor is more likely, and is harder to
check - with the Dec knob, you are turning a shaft inside the gearbox, and
generating the same motion the motor generates, with the RA knob, undoing
the clutch disconnects the drive, and you only move the final drive gear).
However now start with this. With the RA clutch disengaged, verify that the
scope will manually slew smoothly and easily in both directions. If it does,
you have at least proved there is no problem with the main bearings. Now I
say the RA motor is 'more likely'. The reason for this is that during power
on, the scope will move in RA, till the 'index' signal is found from the
worm. However it does not move in Dec, till ordered to do so. If the manual
RA motion is stiff, the problem is with the main bearings/gear.
Beyond this point, the answer will depend on how 'mechanical' you are. You
need to remove the bottom plate from the scope. Details of this are in the
mapug archives. The fact that the scope sounded to be working harder before
the problem struck, suggests that something very 'untoward' may have
happened internally (perhaps a wire has managed to get itself engaged in the
gearing!). There have been many reports in the past of bits of swarf, and
other mechanical debris inside the scope, but these are usually not large
enough to completely sieze the system. Hopefully a visual inspection will
show the problem. If not, it is then going to a case of removing the RA
drive, and looking deeper. Refer back here at this point!....

Best Wishes

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