Updates
Added a new circuitbending article on building an Advanced Probe.
I’ve not actually built one fully - I actually use a prototype breadboard and temporarily solder leads directly on to the PCB. This works great if you can look at a board and know where the V5+ and GND pins are by their location or pin shape (on chips). If you don’t have that kind of knowledge (I’ll write it up later, I promise), or just want a good system for finding bends, the Advanced Probe is a good idea.
I came up with the idea initially when reading Rheed Ghazala’s page on Cautions, which lists warning signs like sparks or batteries heating up. In my opinion, if you’ve reached a point where the chip is getting hot or the batteries are draining so fast they’re getting hot, you’re already potentially damaging the instrument, possibly in a subtle way you won’t notice until later. Just checking the voltage difference before making the connection will prevent this from happening.