do you have an amiga monitor?
My test bench is just a standard switching PSU, a standard jamma harness, an arcade to LCD converter and a PC.
I have a bunch of edge connectors and jamma finger boards that i wiring up adapters for the games i fix.
I have that exact logic probe and this logic analyzer
http://www.saleae.com/logic16I have a really cheap USB oscilloscope that works most of the time.
I usually print out schematics or if i have to, i probe random things trying to find something that doesnt make sense.
I actually learned a bit on how to fix arcade games from your buddy adam's youtube channel. The stuff I fix at work is modern things which in some ways is much easier to fix stuff.