Reddit mentions of Tweezerman Stainless Steel Point Tweezer in Assorted Colors

As was said before, these are rotary encoders.

I had an old piece of gear with these. One knob was broken. I discovered there are many options to consider for what the encoder is:

• switch or no switch - these look like the kind that do not have a push switch
  
• detent or no detent - if the shaft makes clicky feeling feedback when you turn it. I am guessing these don't because they are the tone stack knobs.
  
• The number of pulses per revolution. This is not possible to tell by looking at it. or from detents. But usually these are 24. There are other kinds too
  
• The orientation - vertical or 90 degree. these look like vertical right.
  
• the pin type - surface mount or pc pin. hese look like pc pin.
  
• panel mount or pcb mount. These look like panel mount because the threaded screw around the shaft
  
• encoder tech (mechanical or optical) - these are mechanical
  
• the output type (quadrature, binary) - because the 3 pins, these are quadrature
  
• the shaft length - if the shaft is plastic or metal is not as important. these look like 20mm
  
• the shaft pattern (straight, fluted, or slotted) - these look like slotted.
  
  So probably this https://www.digikey.ca/product-detail/en/bourns-inc/PEC11R-4020F-N0024/PEC11R-4020F-N0024-ND/4699190
  
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  In general, I used their search filters, here is a link to one less narrowed down too https://www.digikey.ca/products/en/sensors-transducers/encoders/507?k=&pkeyword=&sv=0&pv545=142&sf=0&FV=fffc0076%2Ca4019a%2C1140291%2C6240002%2Cffe001fb%2C3400006&quantity=&ColumnSort=0&page=1&pageSize=25
  
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  To remove these from the PCB, you need to be good at desoldering. I used a solder iron with desolder wick
  
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  I have this solder station https://www.circuitspecialists.com/csi-premier-75w-Soldering-Station.html
  
  A good solder station is important as the tip is very fine point, the heat is regulated and can be adjusted. I used about 350 to 400 degrees C heat. And the device is safe to use for static sensitive boards.
  
  And solder wick https://www.amazon.ca/NTE-Electronics-SW02-10-No-Clean-Blue-098/dp/B0195UVWJ8/ref=sr_1_1?keywords=solder+wick&qid=1565443539&s=gateway&sr=8-1
  
  Having some fine tweezers is good too. I have these https://www.amazon.ca/TWEEZERMAN-Stainless-Tweezer-Assorted-Colors/dp/B000782SQY/ref=sr_1_54?keywords=tweezers&qid=1565443795&s=gateway&sr=8-54
  
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  It is very important to not damage the circuit board when desoldering. be patient. The hard part with taking out rotary encoders is desoldering the mechanical support metal clips on the sides. These usually are wider and require more heat and time to melt and more messing with the solder wick to get all the solder out. I recommend desoldering the pins first, using small tweezers to move the pins to make sure they are loose. then work with the iron to alternate the mecanical support pieces to heat and gently rock back and forth.
  
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  Another thing migh to try is to destroy the old broken encoder, small cutters to cut apart the pins and the supports. Just be careful again to not damage the other parts and the board. Then you can easier desolder the loose bits of metal remaining in the holes.
  
  The approach worked well for me. I had a few iterations, since the first time I replaced an encoder, put the device back together, then i found a different encoder had stopped working. So back apart and I had to desolder it as well. But then I went on the learning curve of getting an encoder with the wrong number of pulses per revolution. It was a big wheel for the options, so it had 24 detents, but 12 pulses per revolution, and a push button switch, so some kind of special snow flake.
  
  If these encoders you have here are just regular encoders without switches it should be possible for it to be repaired.
  
  Of course if you don't have the tools already then it can be very expensive to ge them just to do this. I would recommend then finding someone who does have the tools and experience doing this.