Earthshaker: Working on bad circuit boards

Let’s take a look inside the backbox of the game and see what we see…

Now that we’ve identified some issues with the aux power board, we have to deal with it, first by removing components…  Oh by the way… I’ve rightfully caught a lot of flack from the folks on rec.games.pinball about my “bridge rectifier removal technique”… Let me elaborate on that… Korn and others are 100% right in that it’s always bad to try and “force” any components from the board, and if solder is not properly melting, it’s best to re-flow new solder onto the old joint to help remove stuck pins.

I would like to say in my defense, this board was really messed up beforehand.  The traces and thru-holes were already damaged on the board, and I had carefully loosened most of the pins of the BR before turning on the camera, so it looks like I’m using more of a “gorilla” technique than in reality.  So that’s not a good example of the best way to remove components, but I knew already I was going to have to rebuild all those traces and I was a tad impatient.  My bad.

Now we begin work on the actual circuit board and show how to identify broken traces and find where they go so we can run jumpers. Looking at the schematics helps us double check everything.

Now putting the finishing touches on the jumpers and adding the bridge rectifiers…

Now comes the moment of truth, putting the repaired aux power board in the machine and turning on the power for the first time:

So far so good for my first major Sys11 repair.  While I have a few Sys11 games, I haven’t had to do a whole lot of repair work on them so this was a learning experience for me too.

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