ASR 33 buzzing

[drlegendre .]

Tony's suggestion is the best at this point - look for issues with the
motor start and/or run caps. A shorted (or open..) cap can certainly cause
this issue. Shorted and it draws excess current in the cap, open and it may
prevent motor starting / running which likewise draws excess (stall)
current, but in the motor windings.

Also, it shouldn't be too hard to isolate the motor assy. itself from the
rest of the circuit - lift the correct lead(s) from the AC power
distribution system. It may be much easier if you can deal with the motor /
cap assy. as a single entity, rather than within the rest of the complexity.

This is just generic advice from a guy who's never fixed a 33. But assuming
yours has the standard AC synchronous motor, it should all apply. Motors
only draw excess current for a very few reasons - overload / stall, shorted
windings, bad start / run caps and possibly associated start / run relays.



On Thu, Oct 13, 2016 at 11:34 PM, tony duell <ard at p850ug1.demon.co.uk>
wrote:

>
> > The buzzing definitely seems to be coming from the motor.  I put a
> plastic
> > tool to the casing and could feel it vibrating. However, I can turn it by
> > hand (clockwise) and see all the gears and striker mechanisms working.
>
> Should the motor be running in the 'Off' positon of the switch, though?
>
> If the motor is buzzing and taking a high current (which blows the fuse),
> what about the motor run capacitor (the one on the mechanism chassis
> itself, wired to the motor)? Maybe it has failed.
>
> -tony
>