Sir wwjda2z . . . . . .
I needed one more frontal shot . . .to make out . . . that is being their
REGENCY model and showing further details of the front panel.
From my other reads, with all of its accessories, I can now see why you wanted to keep it in service . . . . .as it seems like it reaches its full functionality, just short of being able to walk the dog! ( In circles. )
FRONTAL SHOT . . . . .
https://i.ebayimg.com/images/g/Pk8AAOSw2KNhKQjn/s-l1600.jpg
You did not say if its motor turned any AT ALL ?
I would suggest that you plug the unit in and press the power button 0N and then try the PULSE button, just to see if the motor came to full life for just that moment of its press down.
And then, it should turn off at the instant of release.
The Speed Control Board . . . . .
down at the very bottom . . . .
I find no cross referencing to that house numbered SCR . . . . as is being my suspicion, over a TRIAC and that is likely a DIAC as the marked glass package.
Then, there are two .047 white cased poly caps and a hand full of 1/2 w carbon composition resistors and two calibration trim pots ***..
The latter cluster RC components set up the attack angle and duration period of the trigger pulse to the SCR gate. Them, along with the remoted speed control pot, which also has two trim pots associated with it.
Their initial design research will have ascertained that the mechanical loading presented to the motor by cutting blade action into foodstuffs requires a certain minimum speed, so the main motor speed is set to its minimum and the MIN speed trim pot is used to rev up to that loading level. then the main speed control is set to max speed and its loading level, while the MAX speed trim pot is then set. You should see some fractable sealant that they put on from the trim wheels to cases, to hold those CAL settings.
Motor back EMF feedback into this circuitry also gives a degree of motor speed compensation / correction, relative to mechanical / foodstuffs loading variances.
***
Trim Pot
As well, one might expect some gearing down between the motor shaft speed and cutting wheels in order to get down into that low speed STIR function and its required and effective final torque.
TESTS . . . . .
Note the A &B reference mark ins.
If you were successful on getting the motor to power up in bursts by using the manual
PULSE switch
Then power up and see if a very fast shorting across the A and B mark up points will cause the same unbridled max speed of the motor.
This would be done the safest, via remoting wiring from those two points or use test lead wires /w clips. Or, if attempted manually, PREPARE yourself for the physical motors start up jump / jerk.
If that gets you a running motor . . . . . then we must suspect the SCR itself or else, the loss of its gate drive pulses.
To check for that, place DVM in AC mode and probe between C ground and D and power up to see if there is a . . . .gate drive signal . . . .for you to take a reading of, while you then run the speed control between extremes to see if you experience any change in readings .
Finally move the probes to between E and F to then see if you read the ~25'ish thru 40'ish AC volts, being expected across a DIAC.
Post your results . . . . .
PLUS . . .
You say . . .
As far as I can tell, triac pinout is standard as (left to right) line1, line2, gate.
The way I " read " the board foils , is that as a SCR #1 is definitely Gate and #2 is A and #3 is K .
IF the BLACK wire coming in from one motor wire is being the BLACK wire that connects to #2 of the SCR. ( You have split it up between photos, so I can't confirm. )
Oster food processor whose variable-speed motor is stuck at a single speed
And would that be Slow-Med or Fast ? and the speed control has NO effect ?
ALSO . . .are the GREEN circles being Nylon or Delrin insulated, standard slotted screws . . .therefore . . . . . the SCR tab is being insulated and heat sinked ?
MARK UP . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I'm not 90 . . . . . . I'm only $89.95 plus tax.
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