Thank you @RussD for submitting the video. This is a video of a technician replacing a motorized fader in a DM-24. These are the exact same faders used in the SX-1 so the procedure is the same. This particular tech is using solder wicking braid to remove the solder from around the fader board connections (and he is quite proficient at it!), however, I prefer to use a solder sucker for this kind of stuff.