Ok, this one has been driving me crazy for a few weeks now. When I hit #2 rollover on my World Fair, it is supposed to turn off the playfield insert and light the corresponding #2 light on the backglass. What happens is the backglass #2 light doesn’t always light up or it will just briefly flicker and turn off. It will work fine for 2 or 3 games but the problem always comes back. I thought I had it fixed. It seems to be tied to the #2 make break switch on the reset bank. I’ve cleaned the contacts with one of those ignition files several times. I’ve adjusted the contacts to no end. Made the contacts as close as possible. It will work fine for a few games and then come back. If I just touch the switch very lightly the #2 light will come on. I don’t know if the relay is maybe not pulling in tight enough sometimes to cause it to not make good enough contact. What would cause that? By hand it seems to move fine. The contacts themselves had a white film on it but look better now since I filed them. Replacing these switches would not be easy. I’d probably have to make up a whole new one from parts from PBR or something.

At first I thought it was the bulb or the socket in the backglass. I replaced both. Obviously that wasn’t the issue.

Any suggestions? Thanks.

I did just check the screws. They are tight. Here’s a picture of the rollover switch. Looks ok. I’m trying to get a good picture of the switch in question. I think “floating contacts” is the issue. If I press the contacts just a tiny bit, I can make the light toggle off and on. So why isn’t it tight enough? Maybe new springs on the relay would give it more snap and make it tighter.

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The switch with my finger on the roller is the #2 switch. The contacts in the middle is the make break switch that I think is causing the issue.

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The gap looks looks a little wide in this picture but I’ve tried making it closer or wider. Problem comes back regardless. As you can see the contacts are not the greatest.

I even adjusted the rollover wire to make it stick up higher because it seemed to be lower than the rest of the rollovers. No change.

Thanks. I have tried that also.

I think I may have fixed it. I removed the spring and took out the armature plate for the #2 relay. It was pretty gummed up on the side that faces the coil. There’s a rivet in the center of it. I went over that rivet with a file a couple times to shine it up. Then I wiped it down with Simple Green and put everything back. It seems to be working now. I think that rivet is making better contact now when the coil fires and that may be giving it more snap and pulling it in tighter. That tighter pull in is making tighter contact of the make /break switch. I’m hopeful but time will tell if that’s really the cause.

I spoke too soon. It’s back. It doesn’t matter if the # 2 is hit with the rollover or with the spinning wheel landing on #2. Either way has the same issue. I don’t know what else to try at this point.

Could the coil itself be going bad?

Thanks. It’s not that it’s turning on randomly. It’s that it won’t turn on when it should. All other lights work correctly. The first thing I did was replace that light socket in the back box because I thought for sure that was the problem. It wasn’t. I also put a new bulb in there with no change either. If I manually push the number 2 rollover blades from underneath the playfield, the lights seem to work correctly every time. I can see the # 2 relay pull in correctly. It seems in game play, that # 2 relay is just not working reliably. Works sometimes, doesn’t work other times. It pulls in, but maybe it’s not pulling in all the way. I know when I took the armature plate off, the coil looked kind of strange to me. Like it was kind of gunked up. It may be rust. I will take a picture tonight and post it here. I need to pull another plate off to compare. If I put just a tiny bit of pressure on the yellow roller with my finger, the #2 backbox light will turn on like it should. This is after the relay has been pulled in by hitting the rollover or the spinning wheel landing on #2.

It sure looks like rust on the end of the coil. I don’t have any CLR in the house. I can get some in the next day or 2. I did clean it off with isopropyl alcohol. Quite a bit came off. Can I file the end of the coil or use something else to shine that up or is that a bad idea? Maybe a scotch bright pad? The springs are all there.

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The spring is there. Here’s a better picture.

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It does seem to move back and forth easily. One thing I read last night about make/break switches that I was not aware of. It says that the one contact should open before the other one closes. If that’s true, then I may not have had this switch adjusted correctly. It appeared to be that the one contact was closing before the other contact closed. That second (middle) closed contact is the one that controls the backglass light in question. I compared this to other make/ break switches on the bank. They were correct. This one definitely was not. Does the make/ break opening /closing sequence make a difference? If it does, that could very well be the problem here. I will take resistance readings of the coil and compare to others on the bank. As far as putting pressure on the roller, I have done that when the bank is in it’s normal position. I think I’ve also tried it in the up position also but I will confirm by tomorrow. I may not get back to this until tomorrow but I will report back. Thank you for your help.

I think I got it this time. First, the coil reads 3.7 ohms. It's the same as the other coils. I cleaned up the rust some more. I don't think I'm going to get it any cleaner. Re-ajusted the make/break switch to match the other make break switches. Open the front or top blades first, then close the middle blade when it's activated. Gapped about a 32nd. I've played about 15 games. It worked correctly every time.

I may have one other little issue that I may post a new thread on. Center wheel may be slipping or grinding a little even though everything seems tight. Thank you very much for your help.

Is it difficult to take apart? I’m kind of leary of doing that. I’ve never taken a stepper apart before. What’s happening is that sometimes when it’s finishing it’s spin, the last bit of that spin doesn’t always sound or look smooth. It doesn’t do it all the time, but it’s definitely noticeable when it does it. I can hear an extra bit of grinding of the gears as it’s stopping.

Excellent, thank you. I’m going to attempt this when I get up enough nerve! I think it definitely needs it.