(Topic ID: 164507)

1973 Gtb Pro-Football: Stepper skips Ball 1 / 5; Launcher autolaunches

By SkyKing2301

7 years ago



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#1 7 years ago

I was hoping to spend a little more time troubleshooting this further myself, without having to bug you amazing people for additional help, but I'm almost out of time -- I'm hosting a party/tournament this weekend and I need to get this glitch ironed out.

If you're up for a long read, here's the history of bringing this machine back to life: https://pinside.com/pinball/forum/topic/1973-gottlieb-pro-football-startup-glitchiness ... The last page may provide some insight for Issues 1 & 2, as it did involve some ball stepper troubleshooting.

Where I'm at now ... everything functions perfectly, except for a three little things:

-- Issue 1: Every so often (approx. 2 in 10 games), after ball 4, the ball stepper advances twice -- momentarily lighting up Ball 5, then advancing to Game Over.

-- Issue 2: Even more rarely (approx. 1 in 20 games), it'll advance twice at the start of the game -- momentarily lighting up Ball 1, then advancing to Ball 2.
---- (Note on Issues 1 & 2: It NEVER skips balls 2, 3, or 4. NEVER.)

--Issue 3: Fairly often (approx. 2 in 5 games), when you start a new game, it automatically launches Ball 1 at the end of the startup cycle, WITHOUT pushing the right flipper button.
---- (Note on Issue 3: It NEVER automatically launches the ball on any other ball.)

Thanks in advance. I have a monstrous list of things to accomplish before the party/tournament, but I'll do my best to squeeze in whatever troubleshooting your recommend as soon as I can, to get results.

#2 7 years ago

Hi
Sounds like a score motor switch is gapped too close???
it may be in the 3-5 ball adjustment switches.
I dont have that pin, but thats what I would look at.
also, chk the EOS switches on player unit, ball unit, if it has them.
and chk the outhole switch and relay.
have you cleaned/lubed the step units?

#3 7 years ago
Quoted from Dr_of_Style:

Hi
Sounds like a score motor switch is gapped too close???
it may be in the 3-5 ball adjustment switches.

Could be. Now that I had a moment to look at the schematic, looks like I should start with the Red-Green wire on the AB relay. Considering the AB relay and the AB-reset relay are active in the startup process, I'll have a look there first.

The Red-Green gap is pretty close. I've made an adjustment, I'll put a few games through and see how it does.

#4 7 years ago
Quoted from SkyKing2301:

The Red-Green gap is pretty close. I've made an adjustment, I'll put a few games through and see how it does.

Red-Green on AB didn't seem to do it ... about five games in, it stepped past ball 1. Seems weird that it would do it occasionally on 1 and 5, but not the others -- makes me wonder about the 3-5 adjustment switches ... are these the little spring-loaded pins contacting the ball stepper disc? I'm going to clean those contacts again.

.....and kiddo distraction, guess I'll get back to this later.

#5 7 years ago
Quoted from SkyKing2301:

are these the little spring-loaded pins contacting the ball stepper disc?

they are part of it.
look at the wire that sends the signal to the ball count unit step up coil.
follow it back to each switch in line. chk each one.
the 3-5 ball adjust, i think is a jones plug either on the bottom , or in the head, shud be on the bottom.
if you can, have someone play a game while you watch inside the head. as the game goes on, watch the ball count unit, and see if at each step, the disk aligns with the rivits.

#6 7 years ago

I had the same problem with the game skipping ball #1 and the rivets were not lined up correctly on the stepper unit

#7 7 years ago

Blast, not having much success over here. Rechecked and recleaned the rivets, no luck. Resoldered the wire attached to the pins, no luck. Checked, recleaned, regapped the red/green on AB. Same with white/brown on Motor 1A. Pretty sure I checked orange/black too (but I got sidetracked with fixing some weak lights). Hmm...

#8 7 years ago

Ok, I thought about it some more and went back to read the end of my other thread -- and this post caught my attention ... https://pinside.com/pinball/forum/topic/1973-gottlieb-pro-football-startup-glitchiness/page/3#post-3134060 ... I was thinking something similar here, perhaps vibration of the whole ball stepper unit was causing problems, if the switches weren't adjusted just right. I've gone in and adjusted the switches on the ball stepper again, and it seems to be working properly so far , as I just quickly ran 15-20 "simulated" games through it, and it didn't happen once.

Now I'll work more on the "auto-launching" problem...

#9 7 years ago

While I'm still in here talking to myself....

I looked some more at my old thread and the schematic, thinking about what else could be stuttering or vibrating or just not making good enough contact as the game sets up for Ball 1, and to see what else affects the ball launcher. I checked the connections on P and O, they all looked good -- and I'd replaced their coils recently.

Then I started looking at Q, since that pulls in when the ball is in the outhole, allowing things to advance. I noticed the base plate of the relay was a little loose to the touch... so I pulled it off the rail to take a closer look, and the thing CRUMBLED apart in my hand! A lot of heat over the years (whenever the ball is sitting in the outhole) had made the ends brittle, so both end plates disintegrated and the wire started coming unspooled, lol! Luckily, I had a brand new replacement coil available, so I installed that in its place.

So now, taking a step back: Since adjusting the switches on the ball stepper, it hasn't skipped ball 5 a single time in probably ~40 game cycles. I'm going to tentatively call that issue resolved.

Since replacing Q relay, I ran it through about 20 game cycles. I only had one incident where the motor turned an extra time or two and it advanced past ball 1. However, I also haven't had a single incident of it firing the launcher.

I'm probably going to call it 'good enough' for now, in preparation for the party/tournament, for these reasons:
-- The skipping-Ball-5 issue was the most critical issue, since that could invalidate an entire game. (I COULD have the player play start another game, play ball 1, then add those scores onto their 4-ball game, but that'd be a huge hassle with five other games to monitor.) However, this issue seems to be resolved, so this is a HUGE step forward.
-- The skipping-Ball-1 MAY still occur, but this can be dealt with. If it skips Ball 1, the Player simply notifies me, I throw the tilt and start a new game, which more-than-likely will then proceed to Ball 1 normally.
-- Although it appears to be fixed, the auto-launching isn't really a big deal either. If a Player starts a game, they're presumably ready to start playing -- and so if the first ball launches for them, so what? They're there, ready to rock.

So, thanks to you, reader, for allowing me to talk this out. Also thanks to Dr_of_Style and Spider3582 for pitching in. And finally, thanks again to woz and fredsmythson for helping out in the previous thread, which led me to some probable solutions here.

I'm going to keep this thread open for now, through the party, and see how things go ... and in case you have any other ideas/suggestions.

2 months later
#10 7 years ago

Since my last post, I worked through a little more cleanup and adjustment, and it seemed to stop skipping ball 1 & 5. The auto-launch on Ball 1 still happened on occasion, but IMO, it's not a big deal. Marking it as resolved to close this one out -- and because I traded this game this morning for a nice Top Score.

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