Pictures of BK 2000 underside of the play field

[drhex]

Did you try to short cables at the switch? If so, what is the result? If shorting the rows/columns at the CPU activates all switches as per what you wrote above and you have continuity on the cables up to the switches from the CPU board shorting cables at the switch must work. Just do the simple things first before breaking out the logic probe. Please follow what I wrote above and get one switch to work at the playfield. This will then educate on what needs to be done next.