How about Williams using identically-keyed harness connectors - sometimes in the same color too! - in the System 6 era. When bulletins and guides to "which chips / boards / coils did you fry?" have to be made, ya done effed up on the line.

I'd also say the lack of rectifier fuses until System 11 seems like a bad manufacturing decision too, BUT I wonder if maybe they just didn't understand the risk when they designed their electronic platform.

The Bally -35 rectifier board also seems like a horrible manufacturing design too. "Undersized and hard to work on" always fits the "planned obsolescence" ethos. But maybe they lasted as long as "intended".

Yeah, that's what I was alluding to. There's no question that for the "home use = forever collectible" market, and that same philosophy being applied 40 years later, that board was a terrible design. But of course, that's NOT the environment it was originally designed for, so maybe it was indeed "good enough". So in some ways it's hard to judge.

The Williams gaffes I mentioned, being design/assembly defects and/or safety hazards, are easier to damn.