Here's a list of all my equipment that I use on my bench to fix and troubleshoot video games. I did not instantly get all this equipment in one day.
Most of it was upgraded/purchased over time. You could easily do arcade game work with a $10 Radio Shack soldering iron, a $20 logic probe, and a Soldapullt. However, this equipment
does make life a lot easier (and quicker) when working on anything electronic. As I get more equipment (or use equipment I forgot I had), I'll add it to this list.