When the ball-in-play skipping happens, does the player also get a score, such as 10 points or 100 points? If so, you probably have a stuck switch on the playfield somewhere.

If you hear the loud buzzing and the score is not changing, try tilting the machine or turning it off. If one of the score units advances to the next number when you tilt or shut off power, then you have a stuck scoring switch. The most common stuck PF switch is usually one of the stand-up rebound switch blades located behind a rubber ring.

- TimMe

So, this is only for replay? The first game always plays correctly?

Well, there are a lot of things going on with the ball count set-up on this game, so I suggest that you do a few basic tests (if you haven't done them already) to help narrow down the possible source of the issue you are having.

First, have you operated the ball count step-up arm by hand, and confirmed that it is reliably and smoothly stepping up exactly one tooth each time you operate the lever? Similarly, have you operated the ball count reset arm by hand, and confirmed that it is reliably and smoothly stepping down exactly one tooth each time you operate the lever? You should be able to manually step your ball count unit all the way up to 9, and all the way back down to 1, several times without it ever sticking or skipping. If your ball count unit won't do this when you operate it by hand, then you have a mechanical issue with the ball count unit.

If the above manual test of the ball count unit passes, the next thing to do is check the zero position switches on the ball count unit. This is a switch stack with a make-break switch, as well as at least one other switch that closes only when the ball count unit is at the zero position. Have you manually stepped your ball count unit down to the zero position, and then up from the zero position, and watched the action of these zero position switches? Have you confirmed these switches are transferring state reliably when the ball count unit moves into and out of the zero position?

If the above two tests pass, then the next thing to do is check the game relay. This is a latch-trip relay that controls the reset and also the set-up of the ball count unit at the start of each new game. Have you operated this relay by hand, latching it and tripping it, and confirmed that it is operating smoothly and reliably? Have you checked the switches on this relay, and confirmed they are clean and adjusted so that they make good contact and also open properly, depending on whether the relay is in the latched or tripped state? If the game relay looks good when you operate it by hand, have you watched it while you start a new game several times, with the machine powered up, to see if the game relay ever sticks when it tries to latch or trip electrically?

If all of the above items check out OK, then there is some other problem causing your ball count issue.

- TimMe

You're welcome. One other thought - a good rule of thumb when an issue appears just after you work on a game is to go back and look at what you just did, and confirm that all is well. For example, if you remove the screws you installed to secure the kicker, and let the kicker be loose again, do any of the new problems go away? If so, then you can look for a short, or a pinched wire or something, that may have occurred when you snugged down the ball kicker. If all of the same problems are still there, then at least it will help you to eliminate your recent repair work as a likely cause of new problems.

- TimMe

OK, you are calling these items switches, but I believe you are actually talking about relays (not switches). If you really are talking about a switch and not a relay, please let me know.

It's great that you've noticed that the ball index relay is pulling in sometimes, and that is causing the ball in play problem. That's very good troubleshooting information, and we should focus on that. The ball index relay is supposed to drop out at the start of each new ball in play, and it also supposed to pull in (and stay locked on) as soon as any score is made (10, 100, or 1000).

This brings us back to the issue of a possible stuck playfield switch that I was talking about in post #2. You may have a PF switch that is gapped very close, and is intermittently making contact. The next time you see the ball index relay pull in and cause the problem, turn off the machine and see if any of the score reels advance by one. If so, you have a stuck playfield switch. If not, then the problem may be elsewhere.

- TimMe

Yes, pics would be a big help at this point. Please post pics of the following:

Game relay

Ball index relay

Ball count unit - zero position switch stack

Thanks! - TimMe

Thanks for the pics, they are very helpful. After looking at these, I have two suggestions:

1. On the ball count unit, the adjustment of the zero position switches look pretty good; however, I am wondering if the make-break switch is making good contact with the open switch blade when the ball count unit is stepped up one tooth from the zero position. Right now, the switch gap looks very large to me, so it would probably be good to check the action of that switch, and confirm all is well.

2. The Game Interlock Relay appears to be out of adjustment. It looks like this relay is "kind of" latched, but unfortunately the latch positioning of the two armatures looks wrong. Also, it looks like there are switches on the relay that are out of adjustment. Here is a picture with pointers to the issues I'm talking about:

game interlock relay issues (resized).jpg

The red arrow points to the place where the relay armature latching occurs. The vertical plate should either be totally engaged in the plastic hook that it is touching, or totally dis-engaged from it. Your vertical plate is resting right on the edge of the plastic hook, and that is no good. Check to see if you can fully latch the relay by hand, by pushing the horizontal armature tighter against the coil. If the vertical plate won't latch fully, you'll need to adjust the relay so that the vertical plate lands fully in the hook when the relay is latched, and also so that the vertical plate is totally off of the plastic hook when the relay is released.

The two yellow arrows point to where you have two switches out of adjustment. When I look at the other switches on this relay, they show that the relay is in the latched position. In this position, the two switches with the yellow arrows need to be open, but they are still closed. Note that this may be happening because the relay isn't fully latched (the vertical plate isn't fully in the plastic hook) but in any case, once you fix up the adjustment of the relay latch, you'll need to check the switches on this relay and adjust them as needed so that they make and break properly, depending on whether the relay is latched or tripped.

- TimMe

To adjust the latching of the GIR, you loosen the two adjustment screws holding the trip coil frame, and slide the entire frame around until the latch plates line up properly. Then you re-tighten the two screws. The green arrows in this pic point to the location of the two adjustment screws (note that the screw heads are barely visible in the pic):

GIR adjustment (resized).jpg

The latch adjustment takes a bit of time to dial in properly, because you need to position the vertical latch plate so that it holds the main relay armature all the way against the main coil when it is engaged in the plastic hook, but with just a TINY bit of wiggle room so that the vertical plate can be pulled in by the trip coil without binding.

When the vertical plate is pulled all the way in by the trip coil, the top edge of the vertical plate needs to be positioned such that it has slid totally off the plastic hook, and has allowed the main relay armature to drop all the way open. So you should expect to go through some trial-and-error repetition before you get the latch adjustment to a good place.

The latch adjustment must be done first. After you've got the latch adjustment dialed in, and the mechanical latching action of the GIR is working smoothly, then you can adjust the switches on the relay so that they actuate properly.

The ball index relay is a separate issue. From your description, it sounds like there may be a problem with the operation of the ball index relay. However, you need to get the GIR dialed in first, before doing any other troubleshooting.

- TimMe

I forgot to mention that the adjustment of the switch blades is done by just lightly bending the blades themselves. The amount of bending needed to adjust switch blades is actually very small, so when you first start to try doing this type of adjustment, it's better to use a very light touch. The good news is that if you over-do it, you can bend the blades back the other way. The bad news is that if you REALLY over-do it, you can mess up the blades big time. So the important thing is to go slow, and don't use too much force.

The best place to apply bending pressure on a switch blade is next to the phenolic switch stack. If you have very small needle-nose pliers, you can use that to do the switch blade adjustment. However, most standard needle-nose pliers are too large for this work, so another thing you can use is a very small flat-blade screwdriver, pressing it lightly against one side or the other of the blade next to the switch stack to adjust it.

- TimMe

Sounds like you made good progress. Just curious, did you check the zero-position switch operation on the ball count unit, and confirm that all the switch blades are transferring correctly?

I grew up in Chicago, and lived in Carbondale IL in the 1970s and early 1980s. That's where I was a tech for an operator, Merri-Mac Vending, who had a lot of games and vending machines out on location. We had a couple Hi-Lo Ace games on location when I worked there.

- TimMe

Don't despair, it's all part of the learning process. Fixing an EM pingame is not trivial. We can still try working through the issues via the Pinside forum, if you are up for it. I don't do private long-distance repair advice.

Your pictures can be very helpful, but I need to see very specific pics of very specific things as we go. So, could you please post the following:

1. A picture of the zero position switches on the ball count unit when the ball count unit is set to ball 2 (not ball 1).

2. A picture of the GIR when it is tripped. You picture needs to be a bit closer than the one you just posted, that one is too small to see any details.

3. A picture of the GIR when it is latched.

Thanks! - TimMe