Royal Guard Target Bank Problem

Hi all. I just joined Pinside! Been lurking a while, mostly trying to find a solution to a problem I have with my Gottlieb Royal Guard (1968). I purchased it, mostly working, at an estate sale about a year ago (my first pinball game). I've learned a lot just tuning and cleaning it up, especially about the score reels, omg. Anyway, it works perfectly except one problem I just can't figure out. Hope I can describe it well enough.

Describing this will be rather complicated, so I'm only expecting an answer if you are familiar with the 4-target bank in this game. Please forgive me! Wish I could be briefer and clearer...

There is a 4-target bank that changes positions when you hit certain things, including any of those four targets. A goal is to hit each target in each of the two positions. For each target in one position you hit, a light goes out and another target in the upper playfield lights that then gives 100 (rather than 10) pts. Same thing for the other position, except a bumper lights for 10 (instead of 1) pts. The bank works perfectly when touching the targets by hand, either hard or soft. The problem is that, sometimes, it doesn't work during play.

Before I describe the malfunction, it is important to note that when the bank shifts, each target then actuates a different set of switches, one for each of the two bank positions. To try and make things clear, I'll refer to the switch position, rather than the target position.

The problem occurs when a given switch has been hit for one bank position already. Occasionally, when hitting the corresponding switch for the other bank position, that light doesn't go out nor does it light the corresponding scoring lights. However, I know a switch closed because the bank shifts. I presume what has happened is that the first switch (the one that corresponds to the target/position combo that was already hit and scored) closes before the second switch (the combo that has been hit for the first time), which then shifts the bank without giving the scoring increase. Looking at the schematic, this seems possible (not a good circuit design, imo). I have tuned the switches to close as close to simultaneously when a target is struck as I can, and that helped a lot, but the problem remains.

Unless I am not understanding the schematic, this seems like it would be a generic problem with the RG. Anyone else have this problem? Is there a solution? Am I nuts?

Thanks so much for reading this whole thing!

Huh, I thought I replied yesterday, but I don't see it here. Guess I'm a rookie...

First, thanks for the reply, gottguy! It has been a while since I actively attacked this problem, but I am sure the switches are optimized. I am not, however sure about the relays, so I will check on that and report back. I can say that I haven't seen any scoring issues. I don't see how it could be an activator plate problem, since a switch definitely closes as indicated by the bank shifting. Maybe I don't get something there? I will check on the relays this weekend and post an update, and think more about the plate.

Yeah, that bell is loud! When I first got the game and opened it up, there was some kind of goop on the bells, especially that one. I cleaned it off and then regretted it a bit... ear-splitting with the back off, and unpleasant even with it on! I re-deadened with some vinyl tape strategically placed on the edge of the bell to get the volume more in line.

I love this game, by the way!

I'll look at that more closely. I did go through and clean all the relays, but that didn't help. It drives me crazy that I know a switch closed because the back shifts, but the proper score relay doesn't get activated! I'm guess it happens maybe 5-10% of the time.

I'll check out that bakelite piece. Any ideas how to test whether that is the problem, beyond just observing whether the holes are elongated?

Thanks again.

I have cleaned and gapped that relay. That one was actually my first thought. I haven't had time to get under the playfield to check for elongated holes, and now I'm leaving town for a bit! I'll repost in a couple weeks. I appreciate your being a thought partner on this one!

OK, I was on travel and will be again, but the bakelite piece is definitely and significantly worn. Moreover, I found that if I moved the target lever within the range allowed by the worn hole, I could find a spot where a switch may not close. It is definitely a problem and will fix. When I eventually do, I'll report back whether it fixed THE problem or not.