[HAM] BV and Leslie 147 stuck on fast

[Dave Bishop]

You can download a copy of the Leslie 147 schematic at 
www.captain-foldback.com and see why the symptom you describe is unusual.

The slow chorale speed is caused by de-energizing the larger fast motor and 
energizing the smaller slow motor.  That is accomplished by energizing a 
relay that switches 120VAC current from one set of motors to the other.  You 
energize the relay by shorting cable pins 2 and 3 together through closing 
the Leslie switch at the Chorale position.

Its possible for the relay to become stuck at the fast motor position, but 
the relay is under the 147 amp chassis and it would be unlikely that two 
different 147 amps would both have defective relays.  If you're 
knowledgeable with amps, you can alligator clip a short between pin 2and pin 
3 from underneath the amp to isolate out problems from the cable, connectors 
and switch.  If you get a slow speed with the jumper installed the problem 
is between the amp and the Leslie switch somewhere.  Another way to test 
everything upstream of the leslie amp is to unplug the organ from Mains 
power, unplug the cable at the Leslie amp, set the Leslie switch for chorale 
and put a continuity tester on pins 2 and 3 of the leslie cable.  If you 
don't get continuity, you can work your way up the connection points to 
locate the break.

Its possible that the slow motor is not dis-engaging because it is 
mal-adjusted against its rubber O-ring tire or broken, but unlikely that 
both upper and lower slow motors would go out at the same time.  You can 
check each motor by unplugging the motors one at a time from the amp and 
powering them directly with an extension cord.

Its possible that the male six pin connector at the Leslie amp side has pin 
2 or 3 broken, but unlikely for the same pin to be broken on both amps. 
More likely that the Amphenal connector on the organ side is broken, or 
something inside the Leslie connector box, if any.

Regards,

Dave Bishop