I love WMS 3-7 games! I like to think i am an expert at everything involving the PCBs in this game.

I can fix / rebuild your firepower boards sans some major battery damage. $200 shipped back for the MPU, driver, sound, speech, and power board all rebuilt, cleaned, and tested. I have a few hundred board rebuilds worth of experience. Right now i am running at about 1 month turn around time. Might vary a little bit each way.

3-7 combo proto

Prototype sys 3-7 mpu/driver. This is most creative i've gotten so far on a recreation. I put the connectors where they should go and then free formed the rest of it just putting parts where I thought they would route easily at. I changed up a lot of the circuitry to simplify things like using eight bit chips with output disables (way less 7408s) that probably didn't exist in 1978. Test digit with discreet LEDs . There is a spiderweb on the back to fix the all the dumb mistakes I made on the first try, but it works.

I created circuit boards to build a test fixture (lamp tester, switch tester, sol, power distribution, etc) that came in the mail today. I slopped a bunch of polyurethane on a piece of plywood I am going to use to put a test fixture together soon. Dreading doing the wiring.... Anyone have spare wire harness set that goes from the sys 3-6 master display board to each four satellite displays?

So I have gotten back 4-5 mpus with the display strobe decoder chips blown out. It was a head scratcher about what was killing the chip. I finally figured out what is going on with the help a customer and his picture.... 1J2 and 1J6 are keyed the same. 1J2 is power input to the MPU. 1J6 is display digit strobe output. When you reverse those two plugs you shorting out the decoder chip and putting 12v on one output. Chip craps out and sometimes goes bang.

Looks like system 3-6 had series resistors between 1J6 and the decoder chip that got deleted at system 7. I think it would be a good idea to put them back...

Why the heck did WMS key the plugs the same! Seems quite ridiculous they had seven good options of where to key and they repeated the power input plug pattern with a nearby plug.