(Topic ID: 286205)

Gottlieb Sure Shot - Bonus Count Issue


By ChipS

89 days ago

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Topic Stats

  • 18 posts
  • 7 Pinsiders participating
  • Latest reply 29 days ago by Raff
  • Topic is favorited by 2 Pinsiders

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#1 89 days ago

I posted this to a very old thread last night and decided I better create a new post.

I'm having a problem with Sure Shot's bonus count: When the ball drains, you're supposed to receive 1,000 for each lit ball. But my bonus scoring is sporadic at best. I manually lit up all 15 balls and then drained it. I would get somewhere between a couple thousand and maybe 5,000. I could hear the bonus unit cycle through the three sets of five steps. But it clearly was not scoring 1,000 for each step. Several times I also heard a buzzing from underneath the playfield. I lifted up the playfield and saw the Z relay (Bonus Score Relay) was still energized.

I did what a previous pinsider described in his post: Lit up all 15 balls and then manually closed the outhole switch just briefly - enough to move the score motor 120 degrees and the spring contact in the bonus unit would move 5 positions. I did it again and it moved another 5 positions. Third time it moved another 5 positions. Then the fourth temporary closure of the switch resets the bonus unit. So the bonus unit appears to be working correctly.

But what I noticed was the Z relay energize and often would not stop. So instead of getting 1,000 X 5, it only scored 1,000 points. Sometimes it would do one quick burst, pull a second time and then continue pulling. In that case it would score 2,000 bonus. Sometimes, the coil would stop pulling and then I would close the outhole again and the same thing would happen. Sometimes the Z relay would "pulse" and I would get 2,000. Other times it would stay energized and not release and I would only score 1,000. Sometimes it would stay energized and when I temporarily closed the outhole switch again, it would stay energized through the next cycle and I wouldn't score any bonus for that cycle.

I also manually pushed in the plunger on the bonus unit and manually stepping through each contact. Every one of the 15 contacts worked - and when the Z relay functioned correctly, it would score 15,000 points (1,000 points 15 times). But often when I pushed the plunger, the Z relay would energize and stay energized. I had to manually touch the plastic armature to release it.

At first I thought the spring that releases the armature was not strong enough to pull it back into position. But I replaced the spring with another one that was slightly smaller and it didn't help. I now think that something is causing the coil to stay energized, rather than pulsing five times (for each cycle) like it is supposed to. But I'm not well versed in reading the schematic and can't figure out what is causing it to stay energized. Suggestions?

Sure Shot Schematic.pdfSure Shot Z Relay (resized).jpg
#2 89 days ago

I checked all previous posts to see if someone else had a similar problem. Here's the post that comes closest to my situation:

https://pinside.com/pinball/forum/topic/gottlieb-sure-shot-bonus-score-problem#post-6083556

I used a lot of what Pinplayer01 did to try to diagnose my problem. But so far, no solution.

#3 89 days ago
Quoted from ChipS:

So instead of getting 1,000 X 5, it only scored 1,000 points.

Is there ever any problem with non-bonus 1000 pt scoring?

#4 89 days ago

You've confirmed that the bonus unit is working properly? You can manually rotate the bonus unit and it rotates smoothly and clicks into each position? And when the ball drains, you can physically see the bonus unit working correctly?

Some items to check:

On Add "Bonus" Unit switch - yellow/red wire and slate/red wire - Is the switch clean and adjusted properly? Any damage to the switch contact?

Z relay coil - Is the coil damaged or shorting out? Does the coil look burnt or overheated? Using a multimeter, you can do an ohms test on the coil.

(Interesting to note that the Z coil is powered by 6 volts on this machine...)

https://flippers.com/coil-resistance.html

#5 89 days ago

A bulb tester would confirm whether or not the Z relay is sticking on its own. You could connect at 6 volt bulb (e.g. a #44 or #47) across the Z relay coil solder lugs and then watch to see if the relay is ever active when the light is off. Or you might unplug the game while the Z relay is on to see if it stays on.

If it stays on without power the relay may be magnetized. Is there a brass washer between the base of the relay coil and the relay frame? And is the coil mounted to the frame with a brass bolt?

/Mark

#6 89 days ago

I have a Bank Shot which I believe is the “sister” machine. My bonus skips two usually. They are two of the three two for one target shots ( credit for two balls for one target).
One thing you can do with the game on and the play field up in the maintenance position manually cycle the bonus stepper thru its paces. I get the games to reset to zero by manually actuating the bonus subtract coil. The actual stepper resets past the zero point by spring action. I then manually actuate the add relay on the bonus stepper one click at a time. The bonus stops on each termination point / rivet and you should get an audible chime.
I improved my bonus performance by adjusting the moving part of the bonus stepper to better align with making good contact at each stopping point. Cleaned the contact rivets and lubricated the rivets with dry silicon. I do not believe it is the Z relay
PM me if you want to discuss.
Good hunting

#7 88 days ago

Thanks everyone for the suggestions. I did a bunch of testing and have some answers. In not particular order, here are the findings:

1. The Z Relay coil looks fine - not burnt at all. Resistance checked out at 1.5 ohms which is bit below the spec for that coil (which is 1.8). I also checked the pop bumper coil resistance and it was also a bit lower than specs (1.8 ohms vs 2.1 ohms), so it may be my multimeter is off by a bit.

2. The Add Bonus Unit Switch also appears to be fine and adjusted properly. It also appears to be working properly when the bonus unit operates.

3. There is no problem with the non-bonus 1,000 point scoring. Pop bumpers when lit score 1,000 points every time.

4. MarkG - I did what you suggested with the bulb tester. And the bulb did light each time a contact was made (with a ball that was lit). But what I found was that while the bulb was pulsing correctly, the coil seemed to be continuing to pull - even after the bulb went out. In other words, the bulb would pulse on and off the correct number of times, but the coil continued pulling continuously, rather than pulsing along with the bulb.

I say it seemed to be pulling because I could hear a hum and the armature was pulled in. Sometimes it would release (eventually); other times I had to manually touch the armature for it to pull away.

But that doesn't seem to make sense (to me). If the coil was indeed energized, then the light would stay lit, wouldn't it? When the power is off, the bulb tester is off.

As for the condition of the relay, it appears to be fine. Yes, there is a brass washer between the base of the relay coil and the relay frame. And the coil is mounted to the frame with a brass bolt.

Does this make sense to you?

Sure shot Z relay2 (resized).jpg
#8 88 days ago

Your photo shows a copper band around one end of the coil intended to reduce buzzing. There should be a brass washer on the other end, between the coil and the frame, with the brass bolt passing through it. It's intended to keep the coil off the frame and to keep the frame from getting magnetized.

Quoted from ChipS:

the bulb would pulse on and off the correct number of times, but the coil continued pulling continuously, rather than pulsing along with the bulb.

If the coil stays activated once the power is cut the circuit is fine but there is either a mechanical or magnetic reason the armature won't relax. With the power to the coil cut the spring should snap the armature back to its rest position.

If you can't find a mechanical reason for the binding (switch out of alignment, armature binding on its post, etc.) the armature and frame may be magnetized.

As an experiment you can see if putting a piece of paper or two (or tape) between the coil and armature changes anything. If the frame isn't overly magnetized the thickness of the paper can sometimes keep the armature far enough away from coil to let it work properly.

Ultimately you may want to read up on demagnetizing techniques or look for a replacement frame and/or armature.

#9 88 days ago

Yes, there does appear to be a brass washer on the top.

I'll try your paper experiment and check to see if there's some kind of mechanical reason for the armature not relaxing and will report back.

Thanks for your help!

Sure shot Z relay3 (resized).jpg
#10 88 days ago

I've had two machines with coils that tested OK, but after going thru EVERY other possible option I ended up replacing them and it fixed the problem. Maybe yes, maybe no here of course, but even if it doesn't fix it you'd save time on testing.

#11 88 days ago

Your particular style of coil bobbin does not use a brass spacer washer at the back of the bobbin. The back end of your bobbin has a thick plastic covering around the coil core that provides the correct spacing of the coil bobbin in the relay frame. This photo illustrates the difference. The bobbin on the left uses a brass spacing washer. The bobbin the right (the same kind as yours) does not use a brass spacing washer.

coil backing (resized).jpg

As for the sticking Z relay, have you cleaned and dressed the face of the relay armature? It sounds like your Z relay could be sticking mechanically, rather than being magnetized. Here is a related post that describes the issue I'm talking about:

https://pinside.com/pinball/forum/topic/jumping-jack-scoring-relay-sticks-sometimes#post-6014112

- TimMe

#12 88 days ago
Quoted from ChipS:

Yes, there does appear to be a brass washer on the top.

That pic in your post #9 shows the brass mounting screw, not the brass washer that MarkG was talking about. The thin brass spacing washer (if your relay had one) would be located between the back of the coil bobbin and the inside of the relay frame. However, as I noted in my post #11, your relay does not use a brass spacing washer, so you won't find one even if you take the relay apart (which you should do, in order to clean the inside face of the armature and the face of the coil core).

- TimMe

#13 88 days ago
Quoted from TimMe:

Your particular style of coil bobbin does not use a brass spacer washer at the back of the bobbin.

I wondered about that myself so I dug a little deeper:
Relay Coil types (resized).jpg
I expected the bobbin type to correlate with the coil number but it appears that that's not the case. Apparently the bobbin type evolved away from the brass washer (left) in favor of the plastic cover (right) over time. The newer type was probably cheaper (to manufacture and to assemble) and more reliable since the washer couldn't be incorrectly installed outside of the frame.

#14 88 days ago

Yeah, the bobbin form-factor is not related to the coil part number. Gottlieb updated the bobbin format a few times over the decades, usually without changing the coil number. The earliest bobbins were cardboard and fiberboard, which were updated to plastic in 1960s. The final version of the bobbin with the thick backing came into use in the early 1970s. The Gottlieb part number of that final bobbin version is D-15341, which you can see molded into the front face of the bobbin.

- TimMe

#15 87 days ago
Quoted from TimMe:

As for the sticking Z relay, have you cleaned and dressed the face of the relay armature? It sounds like your Z relay could be sticking mechanically, rather than being magnetized. Here is a related post that describes the issue I'm talking about:

https://pinside.com/pinball/forum/topic/jumping-jack-scoring-relay-sticks-sometimes#post-6014112

- TimMe

Thanks for the advice TimMe, I will check that tonight!

Chip

#16 87 days ago
Quoted from TimMe:

As for the sticking Z relay, have you cleaned and dressed the face of the relay armature? It sounds like your Z relay could be sticking mechanically, rather than being magnetized. Here is a related post that describes the issue I'm talking about:

https://pinside.com/pinball/forum/topic/jumping-jack-scoring-relay-sticks-sometimes#post-6014112

- TimMe

TimMe - you were absolutely right! There was some black gunk on the armature. It wasn't much - I couldn't even feel it when I ran my finger over it. But I used a Q-tip dipped in alcohol and it cleaned right up and now is working flawlessly. You da man! Thanks for you help!

And thanks to everyone else for your suggestions - greatly appreciated!

Z relay armature (resized).jpg
#17 87 days ago
Quoted from MarkG:

A bulb tester would confirm whether or not the Z relay is sticking on its own. You could connect at 6 volt bulb (e.g. a #44 or #47) across the Z relay coil solder lugs and then watch to see if the relay is ever active when the light is off. Or you might unplug the game while the Z relay is on to see if it stays on.

MarkG - I just gotta say, I thought this method of diagnoses was BRILLIANT! I'm gonna try to remember that next time something like this happens.

Thanks!

Chip

1 month later
#18 29 days ago

Hey chip I was wondering if you can help out I need a few photos of the bonus unit on the sure shot the side with the springs on it cheeres.
Raff

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