Regarding connector keys...it was over 15 years ago, but still remember working on a Skateball that was new to me and I had removed one of the connectors on the driver board. Wasn't paying enough attention and after I replaced it, powered up the game and had problems. Someone along the way had repinned the connector, looked like with a pair of vise grips, and didn't replace the connector key. Ouch, lesson learned that day to inspect connectors for keys.

As far as not replacing crimps, aren't you concerned about the number of connector cycles that a given connector may have already gone through? Especially on the rectifier board. You are already replacing crimps, tools available, the parts are cheap. A typical original connector housing on the rectifier board will show some discoloration, usually will have burn marks. All the wires have to be moved to the new connector housing anyway. Just food for thought.

Interesting perspective. I certainly agree that crimping is a skill. I am sure I have well over 1000 crimps under my belt, and my last hundred are much better quality than my first hundred, even the tools I am using today are better than the ones I used 20 years ago with my first crimp. I always thought, and I am sure to have read it on RGP years ago, that the install remove cycle for tin plated connectors was much lower, say closer to 25 install remove cycles? I normally see little to no need to repin display connectors unless there is some sort of problem. Some of them have never been unmated and have a very tight connection.

As far as IDC goes, I have had as many problems with those connectors on old Bally as any other connector. Just luck of the draw I guess. Whenever the shells are missing, someone has usually been up to no good. Of course, there is that one IDC connector on the auxiliary lamp board that is always toast.