Thankfully, this appears to be the last issue for my Space Invaders rebuild, and once again I could use some assistance.

The dead bumpers (the ones with the "50" caps on them up top), along with the rollovers in the horseshoe, do not do anything. I have adjusted switches, checked wiring, all seems ok, but nothing happens. I want to replace the switches, but again no part numbers for them.

Anyone happen to know where I can get replacement switches for the dead bumpers and the rollovers in the horseshoe? Beyond that, any ideas?

So just to try something, I put some deoxit on a business card and ran it through the rollover switches, and what do you know they work again.

Unfortunately, didn't help with dead bumpers, nothing at all happens, even when I short the switch by hand. I am going to check the manual to see if theres a setting for those I missed, otherwise I am stumped. I could have sworn these worked last weekend, so yeah.

Actually, oddly enough they do not. None of them do in fact. What does that mean?

Hmmm, it appears I overlooked repinning J2. I will do that now and see if things start working again.

The MPU is a brand new Alltek board. Repinning J2 didn't help any. It seems pretty obvious there is a disconnect somewhere though.

Ok will do thank you! Right now I am checking all of my board connectors and replacing some pins that I don't like the look of. Then I will move to under the playfield and start tracing wires back.

I have continuity between all switches and both wires all the way back to the mpu. Any other ideas?

Out of desperation I sat down and read the service manual in its entirety and learned about the stuck switch test. I tried it and what do you know, switch 5 is stuck (switch 5 being the dead bumpers and the 4 passive slings). *sigh*

Problem is, none of the switches are actually engaged. Do I need to replace a cap or diode or something?

This is resolved. After doing some logical troubleshooting after figuring out it was a stuck switch it turned out that the leaf switch in the passive sling under the left bumper was the culprit. The leaf switch was bent in such a way that it looked disengaged but was touching halfway up.

That took me a good 10 hours to figure out. Just goes to show that you really have to look deep into these annoying issues, and just gives me another reason to put in new switches.

Thanks for your help, I definitely would not have gotten to the end without it!

On the bright side, my Space Invaders is fully functional! Came in as a paperweight in May, and now it lives again.