Just watched part 2 and 3 in succession. Very informative videos! :) I'm also surprised the board worked as well as it did with the faulty buffer chip. I'm envious of your "multimeter" with digital oscilloscope. Looks handy, I should invest in one of those. :)
I was also surprised that it even booted with the bad buffer. The meter is a ZOYI ZT702S, it's the cheapest scope meter I could find that had a reasonably acceptable UI
