Posted this in a more specific category, maybe I will have better luck here.

After going through the switch check maintenance mode on my Data East machine, I have found that I have one target switch not working. Contact is being made, all wires are soldered and not loose, and I do not see any loose or frayed wires at the switch. I cleaned off the contacts and still nothing.

Any ideas how to locate the problem? It's just this one single switch, the rest of the entire machine works great!

In is the middle switch in the photos..not sure if this helps...

Thanks!
Jim

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So basically BETWEEN a working target and this one? Because all other targets work fine. Or could it be the diode on this switch itself at the bottom? Sorry, a bit new to all of this as far as pinball machines, but I do have a touch electrical experience.

Should be as easy as removing and soldering on a new diode yes?

I don't really know how to read these matrix charts, but attached I highlighted the faulty switch.

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Data East - Back To The Future

Will take a look tomorrow! Thanks!
Jim

Checked this morning. I didn’t see any disconnected or broken wires at the points of contact with the rest of those switches (I didn’t check the rest of the length of wires because I ran out of time).

Hmmm....

Yeah, I did pull on the wires and diodes a bit...I was in a hurry this morning but everything did seem pretty solid.

Yeah, I need to learn how to do that. But that will be after I get back from going out of town for labor day weekend.

Thank you all!
Jim

Back from out of town...I tore down the playfield to give things a good cleaning, then it dawned on me. Would I be able to pass some fine grit sandpaper over the contact points of that leaf switch? I saw someone doing that in a video, but I also read that you should not file these switches. But since sandpaper is much finer, is this ok?

I still have not checked the switch matrix to see if there is a break somewhere, but thought of trying this first before I go down that route.

Thanks!
Jim

Yeah, I did try some alcohol and a q-tip the other day but still didn't work (so i thought maybe I needed to go a little coarser with sandpaper). So now it seems like there is a wiring issue somewhere...or the switch itself has just gone bad (is that possible, and I may just need a new switch)?

Jim

Yeah I was going to do that next either way, just trying to see everything that it COULD be. Ill report back if I find anything out! Thank you!
Jim

Well I’ll be dammed. Leaf switch is suddenly working again. I removed the switch assembly from the play field to make continuity testing easier, turned out the switch itself was fine. Re attached the assembly to do further testing and it all of a sudden is working again!

I realized that while trying to fix the switch, I was also in process of upgrading the whole machine to LED's. It didn't even occur to me at the time, but one of the original insert bulbs was burned out right next to the switch I was trying to fix...when the switch finally started working, I realized a new LED was in.

Could the switch not have worked because the bulb was out? Or is there some other miracle why it is now working...

Jim

EXACTLY! Thanks guys!
Jim