(Topic ID: 254587)

Grand Prix- left bonus unit advancing too much?

By pindude80

4 years ago


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  • 28 posts
  • 7 Pinsiders participating
  • Latest reply 4 years ago by pindude80
  • Topic is favorited by 2 Pinsiders

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IMG_20191104_204427 (resized).jpg
Grand Prix 500 relay (resized).jpg
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Grand Prix Left Spinner Unit (resized).jpg
IMG_20191101_200158 (resized).jpg
Grand Prix Left Advance relay (resized).jpg
#1 4 years ago

I got a grand prix not too long ago and tonight was the first time I had a chance to pull the glass and take a look at it. When I would get a good rip on the left spinner it would advance the bonus level more than if I got approximately the same rip on the right spinner. I did notice that when landing in the top saucer after ball launch if left bonus advance was lit I would get 10k, two steps in bonus, but if the right advance bonus was lit I would only get 5k, one step in bonus.

It was suggest to me to check the right spinner switch but I know it's working right because the score reels advance properly for every revolution of the spinner. I figured out which relay under the playfield is activated for each spin of the spinner. I cleaned all of the switch contacts and re-gapped the switches. One of the orange lights that count up on the playfield wasn't lighting. I cleaned the contact for that wire on the mini-stepper but nothing I did tonight changed anything to where both spinners operated the same.

So, I'm wondering if there is a connection between getting more bonus on the top saucer for advance left versus advance right and how I get more bonus on the left spinner than I do on the right spinner. Does this clue anyone into something that I need to look at?

#2 4 years ago

On most of the units there is a screw for a longer or shorter travel of the plunger.
If so, try to turn it in until it takes just a bit more then one tooth, preventing it from a "overtravel" and getting to the 2nd one.
It is mostly a mechanical problem...

#3 4 years ago

I think that is part of the rules look at the manual it says something about saucer and 5k and so on with arrow lit. hope this is what you are talking about.

#4 4 years ago

On my GP I get two advances of the bonus (left or right) when the ball goes in the top saucer regardless what the red arrow indicates. I always try and watch Youtube videos to compare my game to see if it is playing correctly or not. Here is one that shows it advances 2 when the ball lands in the top saucer.

As far as the spinners, there are little mini steppers for each one under the playfield. Make sure those are clean and work. There should be 3 wires on that mini-stepper that advance the bonus 3 times every time the stepper does one revolution (10 spins). I made mine harder by removing 2 of the wires so the bonus only advances one position when the red insert under the spinner goes from the top one to the bottom one. Basically advance one bonus position for 10 spins rather than 3.

#5 4 years ago
Quoted from wizardblom:

On most of the units there is a screw for a longer or shorter travel of the plunger.
If so, try to turn it in until it takes just a bit more then one tooth, preventing it from a "overtravel" and getting to the 2nd one.
It is mostly a mechanical problem...

I think there is a screw like you are talking about but I will have to look closer to verify. I'll report back after I look into it. Thanks for the info.

#6 4 years ago
Quoted from Pinmasher:

I think that is part of the rules look at the manual it says something about saucer and 5k and so on with arrow lit. hope this is what you are talking about.

I found a jones plug on the bottom side of the playfield that you can change that gives you 1 or 2 bonus advances for landing in the saucer. I changed it last night and I still get more bonus advance on the left side than the right regardless of what I have it set for.

#7 4 years ago
Quoted from pindude80:

I found a jones plug on the bottom side of the playfield that you can change that gives you 1 or 2 bonus advances for landing in the saucer. I changed it last night and I still get more bonus advance on the left side than the right regardless of what I have it set for.

I’m thinking your clock spring on the left bonus advance unit is a little loose or too tight. Try unhooking that and wind it one more turn one direction and see if that helps. If not, put it back where it was, then wind one way in the opposite direction and see if that helps.

Glad you got a Grand Prix dude! Worst case you know Jeff Lawton will get you sorted.

#8 4 years ago
Quoted from schudel5:

As far as the spinners, there are little mini steppers for each one under the playfield. Make sure those are clean and work. There should be 3 wires on that mini-stepper that advance the bonus 3 times every time the stepper does one revolution (10 spins). I made mine harder by removing 2 of the wires so the bonus only advances one position when the red insert under the spinner goes from the top one to the bottom one. Basically advance one bonus position for 10 spins rather than 3.

I found these mini steppers last night and looked at them. They both step freely if I manually activate them. These appear to be connected to the orange lights above the spinners, do they also play a part in advancing the bonus? Are these steppers the ones that are not recommended to take apart to clean? As mentioned they move freely but the contact board definitely would benefit from being cleaned.

If I spin the spinners slowly by hand I get 2 advances per every 10 revolutions of the spinner- 1 advance at 6 spins and another advance at 4 spins. I am not certain but I think this is only true if it starts on the bottom most light being lit. So I was trying to figure out if the bonus advanced by the number of spins regardless of what orange light was lit to start with or if the bonus only advanced when certain orange lights lit. Does anyone know the answer to this?

#9 4 years ago
Quoted from chuckwurt:

I’m thinking your clock spring on the left bonus advance unit is a little loose or too tight. Try unhooking that and wind it one more turn one direction and see if that helps. If not, put it back where it was, then wind one way in the opposite direction and see if that helps.
Glad you got a Grand Prix dude! Worst case you know Jeff Lawton will get you sorted.

I was thinking it was something like that also or an adjustment like wizardblom mentioned above. I'll take a good look at the left bonus unit next time I get a chance to see what's going on and will experiment with the adjustment screw wizardblom mentioned and the spring on the advance like you said.

I'm really glad I was able to get this game and add to my collection. It's a game I've always thoroughly enjoyed and I finally found a decent example at a decent price and the seller was great to deal with; I had Bob Cunningham bring it to me from Minneapolis- great experience all the way around. I need to get Jeff to come over to sort a couple other problems on a couple of my other EM games so if I can't get this figured out soon I'll just add it to the list of things for him to check out!

#10 4 years ago
Quoted from pindude80:

and will experiment with the adjustment screw

Before adjusting the travel of various stepper arms please verify whether the Left Advance relay fires every time the Left Bonus Unit advances. It could be that the Bonus Unit is working correctly and is just doing what it is being told to do.

Quoted from pindude80:

If I spin the spinners slowly by hand I get 2 advances per every 10 revolutions of the spinner- 1 advance at 6 spins and another advance at 4 spins. I am not certain but I think this is only true if it starts on the bottom most light being lit.

The Left Spinner switch fires the Left Spinner relay which advances the small Left Spinner Unit stepper. The Left Spinner Unit stepper has ten steps as shown in the schematic:
Grand Prix Left Advance relay (resized).jpgGrand Prix Left Advance relay (resized).jpg
When the Left Spinner Unit is in the 6th or 10th position it fires the Left Advance relay which advances the Left Bonus stepper. That gives you the two bonus increments per 10 spinner turns. The 3/5 ball adjustment jack will allow the bonus to advance a third time (at position 3) if it's in the 3 ball position.

I suspect that your Left Advance relay is firing more than it should. If you can verify that it fires every time the Left Bonus advances we can drill down into what could cause that.

BTW the specific game rules and lots of other helpful information is in the game manual on ipdb.org.

/Mark

#11 4 years ago
Quoted from MarkG:

Before adjusting the travel of various stepper arms please verify whether the Left Advance relay fires every time the Left Bonus Unit advances. It could be that the Bonus Unit is working correctly and is just doing what it is being told to do.

I did a little experimenting and both the left and right advance relays fire when the bonus units advance. I also took a closer look at the behavior of the bonus advance from the top saucer. When I had the jones plug set on 2 advances the left advanced 2 but the right side only advanced 1. I changed the jones plug to 3 advances. The left side advanced properly 3 times but the right side only advanced one time. Now I'm wondering if the left side is working properly and the right side isn't working properly. This would make a little more sense to me since a good spinner rip on the right side doesn't advance like I think it should, how the one in the video above advances- but that game is set on 3 ball, and how I remember other Grand Prix games that I've played advancing with a good spinner rip.

#12 4 years ago
Quoted from pindude80:

Now I'm wondering if the left side is working properly and the right side isn't working properly.

Great observations and I agree with your assessment. Time to break out your meter. Unplug your game and clip your meter between the yellow wire and the yellow-blue wire in the schematic above on the Left Spinner Unit stepper. Manually advance the stepper and watch the resistance between those two wires. Depending on your game setting (3 or 5 ball) you should find 2 or 3 positions where the resistance through that unit drops to an ohm or less. That tells you where the Left Advance relay would fire if you were playing the game. Convince yourself that you can identify where those 2 or 3 positions are that are working correctly.

Now move your meter to the Right Spinner Unit stepper and clip on to the (same) yellow wire and the white-blue wire. Repeat the experiment and see if you can find the 2 or 3 positions where the resistance through the stepper drops to an ohm or less. If you can't find as many positions as you found on the Left stepper you know that the problem is somewhere between your probes in the Right Spinner Unit stepper.

#13 4 years ago

Can you tell if I have this hooked up to the correct wires? I am not getting any change on the meter reading at all when stepping the mini stepper. I'm thinking maybe I have the wrong yellow wire?

IMG_20191101_200158 (resized).jpgIMG_20191101_200158 (resized).jpg
#14 4 years ago

I doubt its in the stepper it basically cannot be, thats not how the jones plug switch could ever work to make rhat change. The stepper sends a signal through every contact at every rotation. Its whoch contact and which switch closure on another ray that determines this. You need to go find where in the schematic the jones plug program to advance one two or three is actually executed. You also need to look hard at the jones and make sure wires and contacts look good.

Always remember to interpret others advice through your own experience and the manual and schematic. I own and have extensively restored this game so I am posting because I think your looking up the wrong tree... but I did not go through schematic so i could be wrong. Just FYI.

#15 4 years ago

Schematic and manual are both on IPDB. Also- manual is incredibly informative and very very packed with useful info. Not sure if your using them but you absolutely need to be doing so.

#16 4 years ago
Quoted from pindude80:

Can you tell if I have this hooked up to the correct wires?

Have a close look at the manual pages dealing with the Left and Right Spinner Units and compare them with the schematic:
Grand Prix Left Spinner Unit (resized).jpgGrand Prix Left Spinner Unit (resized).jpg
One thing I can see from your photo is that you're probing two sides of the Spinner Unit where all the wires you're looking for are on the same side.

If you look closely at the diagrams above you can see that the yellow-blue wire on the left spinner is wired to the copper trace ring around the center, and that the yellow wires get connected to the yellow-blue in only two of the 10 steps as the wiper advances around the contact board. The yellow-brown wire is the optional third connection.

Once you understand the Left Spinner diagram above you should be able to verify that you're getting 2 or 3 connections in 10 Left Spinner steps. Then you should be able to identify the wire colors and connections for the Right Spinner using the diagram in the manual and repeat the experiment. This should tell us whether the Right Spinner Unit is the culprit, or if the problem lies elsewhere.

#17 4 years ago

My point is that the advance every x switch is failing. It ALWAYS sees an advance every X and the fact that yours ADVANCES at the wrong interval DOES NOT mean there is any issue in wires from the spinner. Your wasting time. A switch or another component had failed to BREAK that connection. The fact it works on whatever number of spins it does now, indicates that somewhere there is a switcg stack or contact that should be rerouting the signal and ignoring the trigger your seeing it fire at. It failed to take the command from the jones plug change. Its not the spinner or highly unlikey to be so.

Maybe I am wrong. I will not post again so as to leave this alone. Maybe its late....

#18 4 years ago
Quoted from MarkG:

Have a close look at the manual pages dealing with the Left and Right Spinner Units and compare them with the schematic:
[quoted image]
One thing I can see from your photo is that you're probing two sides of the Spinner Unit where all the wires you're looking for are on the same side.
If you look closely at the diagrams above you can see that the yellow-blue wire on the left spinner is wired to the copper trace ring around the center, and that the yellow wires get connected to the yellow-blue in only two of the 10 steps as the wiper advances around the contact board. The yellow-brown wire is the optional third connection.
Once you understand the Left Spinner diagram above you should be able to verify that you're getting 2 or 3 connections in 10 Left Spinner steps. Then you should be able to identify the wire colors and connections for the Right Spinner using the diagram in the manual and repeat the experiment. This should tell us whether the Right Spinner Unit is the culprit, or if the problem lies elsewhere.

Thanks for taking the time to further document and explain the procedure. I studied the diagram you provided and performed the test again. On both left and right spinner stepper units I am getting 2 connections for every 10 steps and on both units; game is set on 5 ball.

Two things I noticed kind of weird; I don't think they matter, but thought I better mention them just in case. The yellow wire on both units is at position # 6 and not 5 as the diagram you provided shows them and on the left spinner unit one of the connections was showing 5 ohms on the meter when it first made contact then it would slowly drop back to about 2 ohms or so but that could just be something flaky going on with my meter because the other connections showed right around 1 ohm, give or take, as you mentioned.

#19 4 years ago
Quoted from pindude80:

On both left and right spinner stepper units I am getting 2 connections for every 10 steps and on both units

That would remove the Spinner Units from suspicion as @rufessor suggested. To confirm you should be able to manually close the left and right spinner target switches 10 times each with the game on and see both Bonus Advance units step twice.

And we're still working under the assumption that the Right Bonus advances each time the Right Advance relay fires, right? That would reduce the chances that there's a mechanical issue with the Bonus Advance stepper.

So we're still hunting for a reason that the Right Advance relay periodically misses a pulse. There are just four paths into that relay:
Grand Prix LR Advance relays 3 (resized).jpgGrand Prix LR Advance relays 3 (resized).jpg
The top path goes through a switch on the Top Eject relay then through another switch in the Change relay. Most of this path seems to be working if the Left Advance relay is working as expected. It's possible that the Make/Break switch on the Change relay isn't working properly on the Right Advance relay side (green-white wire to green-orange wire) so that's worth a closer look.

The next path to the Right Advance relay goes through a switch on the Right Standup target. That shouldn't be a factor here.

The third path goes through the Spinner Unit and you seem to have proven that that too is behaving as it should.

The bottom path is the lock in circuit for the Right Advance relay. It holds the Right Advance relay on once fired until the advance arm on the Right Bonus unit has taken a full step and opens its EOS (End of Stroke) switch. If the EOS switch isn't opening reliably it's possible that the Right Advance relay stays energized longer than it should and might miss a subsequent pulse. It too is worth examining closely.

#20 4 years ago

I manually spun both spinners and am getting both bonus advance units stepping twice per 10 spins.

I took a good look at the green/white and green/orange wires on the make break; everything is good. I even cleaned the switch contacts to be sure.

The EOS on the right advance bonus is working properly but I went ahead and cleaned the contacts to be sure.

When I had the playfield up manually closing the right advance relay I stumbled upon something that might be a good clue for us. I noticed everytime I closed the right advance relay a chime would ring and the 500 relay on the bottom side of the playfield would activate. I manually closed the left advance relay and no chimes ring and the 500 relay doesn't do anything. I even switched the change relay via the switches by the upper saucer and got the same result no matter if advance right or advance left bonus was lit. I made a video showing this:

#21 4 years ago
Quoted from pindude80:

I noticed everytime I closed the right advance relay a chime would ring and the 500 relay on the bottom side of the playfield would activate.

Hmm. That is odd. The 500 relay is in the DC part of the circuit and should be independent:
Grand Prix 500 relay (resized).jpgGrand Prix 500 relay (resized).jpg
Note however that both the 500 point relay and the Right Advance relay have a switch on the Right Stand Up target. There could be a short between the switches on that target that lets power from the Right Advance relay fire the 500 point relay too. I don't know if that's the root of your original problem but it's probably worth looking in to.

#22 4 years ago

I am assuming this is the lower right target they are referring to? I checked all 3 switches on the lower right drop target with my meter and they show open and closed. I was messing around, and you probably already know this, but the 500 relay only fires twice per 10 spinner switch completion I.E. each time the right bonus unit advances.

Is it worthwhile to disconnect a wire on the 500 point relay to take it out of circuit and see if that changes anything?

#23 4 years ago

The wire colors on the schematic will confirm whether you're looking at the correct switches. Rather than disconnecting anything you could put a piece of folded paper between the contacts of suspected switches to see if the 500 relay still fires. Try the paper between the contacts of all of the switches leading to the 500 relay shown in reply #21 in various combinations (all, none, standup targets only, 500 relay switch only) to see if you can determine which path is activating the 500 relay when it shouldn't. If you block all three switches and it still fires there's a short elsewhere like on the solder tabs.

#24 4 years ago

Just to be sure I'm testing this properly I have a few quesitons. I don't see any colors on that line of the diagram for the right standup switch. Are the wire colors brown/black and yellow that feed into the switch? Are the switches I want to use the paper on both of the standups and the switch on the 500 relay that is red/brown and brown/black?

Thanks for all of your help and guidance along the way

#25 4 years ago
Quoted from pindude80:

Are the wire colors brown/black and yellow that feed into the switch? Are the switches I want to use the paper on both of the standups and the switch on the 500 relay that is red/brown and brown/black?

Yes, both standup switches connect brown-black to yellow wires. The switch on the 500 relay connects brown-black to red-brown instead of yellow.

#26 4 years ago

I found and fixed it!

It was the right stand up target but it wasn't the brown/black to yellow part of the switch, it was the other contact on the switch that I have the alligator clips on in the picture- the brown/black and green/orange. I was wondering why I didn't catch it at first when I looked at and tested the switch. I saw that the switch contacts were touching when I went to put pieces of paper in for our test.

Many many thanks for guiding me through this and telling me what to look at and test!

IMG_20191104_204427 (resized).jpgIMG_20191104_204427 (resized).jpg
#27 4 years ago
Quoted from pindude80:

I found and fixed it!

Well done. Did that fix all of the issues or just the last one?

The mid 70s multiplayer EM games seem to have some of the most challenging issues...

#28 4 years ago
Quoted from MarkG:

Well done. Did that fix all of the issues or just the last one?
The mid 70s multiplayer EM games seem to have some of the most challenging issues...

It fixed both issues- the top saucer now advances the same number of times for both left and right, which is currently set on 2, and when I spin the right spinner it advances properly. I really thought I wasn't going to be able to find/fix this one.

I have a few EMs and this one definitely has the most components to it compared to my other games. I was trying to think if there was a lesson to be learned or something I could have done differently to find this quicker and the only thing I could really think of was when I noticed a problem go through and look at all of the switches, starting with the playfield switches, to see if I see anything not correct. I'm thinking the previous owner accidentally got something caught on this switch like a rag or something when shopping it causing the problem(s) we saw.

Seriously, thanks again and if you are ever near Cincinnati OH I would love to have you over to hang out and play some pin!

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