Gottlieb Volcano System 80, model 667

Finally, I have a mechanical issue for a change.

The yellow drop targets at the top of the playfield started acting up. Coincidentally, the one target I bombard the most is the one giving the most trouble, but it's two specific ones I think. Anyway, when the targets reset, sometimes one target will not stay up. Since the game resumes with a target already down, the target bank will not reset when the rest are knocked down.

So I pulled the unit out, visually inspected, wiped out some dust, and manually operated. It all seems good when I pull the lever by hand. But maybe 10% of the time during play one flag or another will not latch in the up position.

What is the cause of this? Worn out target? I think I replaced all of these targets in 2012, but I didn't touch the game in all this time so there has been very little wear. Weak springs? When I compare to the other bank, the red drop targets seem to be stiffer and take more force to trip down. That's why I'm thinking springs are worn out.

I also made sure there is clearance. I had thought maybe they were rubbing on the rubber behind; I adjusted so the fronts fully clear the wood slot but the backs also do not rub the rubber.

Suggestions, ideas, thoughts?

Thank you!

That’s just it… I could not replicate the issue by hand. I’ll try it again slowly.

frenchmarky -

I cannot replicate the issue manually. However, this bank is functioning somewhat differently, more sloppy, than the red bank. If you watch the video, I go very slowly and you can see the flags click into place one at a time from right to left. On the red bank, no matter how slowly I move the plunger, they all click in simultaneously. I'm guessing it should operate more solidly like the red... the question is which parts are worn out to cause this?

When operating manually, they always click in from right to left. The target giving the most trouble is the 4th from the left. The one giving the second most trouble is the 1st on the left. So the problem I'm seeing does not seem to have anything to do with when each flag clicks in.

Figured it out, I think.

First off, I was not manually operating it properly. My fat thumb was over the lever when it should have only been touching the plunger. When just moving the solenoid plunger, there was not enough travel and only one flag on the far right was latching. No matter how hard I pushed the plunger, the flags would not come up enough to latch. So apparently, only the momentum of pulling on the lever fast/hard enough was achieving any reset.

As per @frenchmarky's original suggestion, I moved the solenoid adjustment. Only by about 0.030-0.040" (~1/32). Now they all latch simultaneously without bottoming out. I also adjusted the top and bottom plates inward by the screw-hole-slop to get more plastic clearance at the top & bottom.

Thank you!

For good measure, I disassembled and cleaned the assembly. I also flipped some of the springs so the loops all face same direction, and shuffled the targets around. (not shown in video)

Seems to be functioning as normal.

Thank you frenchmarky !