It got much worse since originally posting this thread, but the problem ended up being totally electronic in nature. I was able to resolve the issue (and I think all of the issues I have had with the cutter's reliability since I purchased it second hand a couple of years ago) by replacing the K7 relay. I reached out to MBM tech support and they indicated that it was probably a weak relay and that I should replace the board. I figured it wouldn't hurt to try to replace the relay myself first as I had just dropped a few hundred on a new brake and it totally worked. There was quite a bit of carbon build up between the old relay and the PCB, but I couldn't see it until I took it off. I also noticed a ton of carbon build up inexplicably on the top of the electronics enclosure (visible when you took off the front cutting bed) - not at all sure how it ended up there through a vaguely sealed box.
I had trouble finding PCB-ready relays either locally or online, so I ordered some omron PY14 sockets online and picked up quick-connect omron MY4 24dc relays from my local electronic store. Popped them and I am all set! And it will be a plug and play fix if / when it happens again. My cutter was made in 1995, but it looked like the board was last replaced in 2006. I can't help but wonder if it was because of a failed relay then.
The cutter moves a bit slower than before, but I think its because the brake is stronger. The old brake wasn't totally worn out, but I could definitely see some wear on the tips of the teeth.
Does anyone know if there is a proper repair manual for these things? I nice one sheet with some detailed instructions came with the brake - is there something that compiles that information for all of the parts?
Thanks again!