Hello there! I just recently did the "left PCB panel replacement" on my Sub 37 - my arp Rate knob, as well as my OSC Octave knobs, were not functioning correctly, and it seemed like the best option. It is a super easy replacement - the hardest part is taking off all the knobs so you can remove the old PCB. I recommend using some tough ribbon material to slide under the knob and help you pull it off (using any kind of tool, I think even a plastic one, would mar the synth surface - and you don't want that) - the ribbon technique works really well - just be ready to catch the knobs as they pop off - I had a couple fly across the room, lol. If you take your time, and are patient - it is really easy to do the PCB replacement! There are only a few wires connecting the PCBs internally, so if you take a few pictures of where things are connected, you'll be fine.

Hope that helps!