Hello All, I’ve got some time on my hands so decided to fix some lingering problems on my pinball collection. I am on my Gottlieb Sky Jump at present. The machine is in great shape all considering, it came from a basement where it had been since new and has never seen commercial use. I love it.
The problem(s) with the Sky Jump are as follows,
1. Putting a coin in the slot does not give credits.
2. The score reels do not reset to zero when a game is started.
I disassembled the credit wheel, tested the coils and replaced the sleeves, and cleaned it all up and it’s working fine. The game plays and scores fine otherwise, it just does not give credits with coins or reset to zero when a game starts.
I am pretty good with electronic machines, but this is my first/only EM so a little out of my element here. I got a single player for simplicity....
Thanks in advance for any and all help.

Okay so I pulled the scoring reels and cleaned them, cleaned the switches and put them back in, still no reset on game start.
I also noticed that the hundreds reel does not add to thousands and just turns over at 900 without clicking the thousands, so I looked again and my hundreds reel is different it does not have the third switch in there and has no brown cover, see picture. Is this the root of my problem? If I am understanding things this is what counts the numbers up and triggers the next highest reel. I do have a manual. Just want to know now if my hundreds reel is missing a part and need to find. It appears to be wired from the factory in this way.

AB6DA8D9-FB5F-4B82-A310-7072C7AB414B (resized).jpeg

Follow up to the last post. I believe the 100s reel does not have a Bakelite cover because it’s not used in the match or high score/replay? I will double check the score reel switches again. Ugh.

Yes that is what happens. The game plays as normal, score does not reset. The coin slots do not put credits on the machine.

After adjusting and cleaning all the score reels, now it does not go from 9-10,000 points. I double checked all the score reel switches and they are correct. All the scoring is correct otherwise. I can take apart a decagon and re assemble in my sleep now...

I will check the a relay and do the coin switch adjustment and AS relay adjustment as per the manual and see if that helps after dinner and the kids are in bed.
I sure appreciate the help.
And to think I chose fixing this one over a switch matrix issue on my Fish Tales because I thought it would be quicker and easier...lol

Thanks Howard,I’ll have a look.
Love the place up there in Lyons. I play there whenever I come to the front range.

Update, I fixed all of the machine scoring, it’s all working correctly, even lit/not lit values etc.

The game starts and plays fine. The drop targets re set as does the ball in play. The ball kicks out of the out hole and the credit wheel loses one credit.
Two things are not happening, the coin slots are not adding credits to the game and the score (it’s a one player game) does not reset to zero.

I will go through the startup sequence tonight and I made some jumpers to diagnose things. When a coin is put in, the motor spins but nothing happens. The coin mech is working and when a coin is dropped in the motor spins but nothing happens.
When the reset button is pushed the game subtracts a credit on the credit wheel and starts up. The s relay fires, motor turns, targets reset and ball kicks out, just no score reset. I will look through the lined articles and go thru the sequence relay by relay. Im gonna get this thing running perfectly if it kills me. Thanks everyone.

Hey do any of you fine folks know where I might get a full schematic for Gottlieb's Sky Jump?
I have an owners manual, all the score cards etc, but no schematic.
Thanks in advance.

Okay Thanks Billl - Will order one tonight after work.
If anyone has a partial schematic for the game reset circuit(s) and/or credit from coin slot circuit(s) so I could work on this tonight, Id be forever in your debt.
The game score re set circuit is most important.
Thanks Jamie

Yep - that is where I was heading next. I think I am very close.....
Everything is intact, the game overall is in great shape.
Labels are all there still. I dont think the A relay is firing and I can trace it to the switch on the motor I think.

So I pulled the S relay and cleaned it and replaced it, and noticed that the plate on the bottom relay on the A relay was out of place. I am going to clean the switches and replace it, but I was checking things with a jumper wire and the 2nd relay in the A relay, I think this is what is called an interlock relay did not appear to be working. Nothing was happening visually with the A relay. Well I tested both solenoids on A and one had 2.5 ohms resistance (which is normal I think) and the bottom horizontal one had 15.7 ohms resistance. So I have a few questions.
1. How does this A relay work, an interlock relay with two small coils and two metal plates?
2. Does 15.7 ohms resistance mean this solenoid is bad? it’s identical to the other in the A relay.
3. Unrelated - what does a hold relay do? Does it just shut things down when a tilt or slam tilt is actuated? Should it ever be actuated unless a tilt or slam tilt switch is closed?

I did find the schematic, so I think with a little more time and getting some practice with the jumper wire thing, I will get this thing running again.
Thanks

Ok an update I have now gotten the A relay to fire, after the S relay and the hold (R) relay comes on as it should, but the A relay now causes the score motor to run and it does not release the Ax interlock, so I will check the zero switches on all of the score reels and the switch on the score motor tonight and see where this gets me. Thanks everyone the video on interlock relays was great. I am really getting a feel for this technology. Any input is appreciated, but I will simply use the schematic through the reset sequence one by one and see where that gets me.

I found the issue to resetting the A relay. It’s a switch 2B on the motor, the bottom stack outer switch. It’s below the cam and triggers off the post and a leaf type actuator on the inside, not a stiff metal one. I am having a bear of a time getting it adjusted right, it either does not trigger the reset relay, or stays shut. I can see a green spark on it but it still does not actuate the reset unless I adjust it to the point where it stays closed.
I just gotta find the sweet spot I guess. Any suggestions from the pros? Seems like it might be the whole stack is out of whack.

Yes, I have it’s an A786

It’s not the switch, it’s the ax relay interlock release. I can un pin it, and it works every time in my hand, but then when I pin it back in place, it will lock but does not fire hard enough to release it. I guess clean it up? Any suggestions. Getting a little frustrated.

Yes that’s what I am saying.

Ok so I got the machine starting up and playing correctly, scoring and all. I have one last issue and it’s that I cannot put credits on the machine without manually operating the coil in the credit wheel. It takes the credits off just fine when I press the start button. The motor turns when I hit the button or put in a coin, just no credits on the credit wheel. Can any of you fine gentlemen walk me through how to jumper the coil back there? I know the idea of it all, but just am having trouble actually finding the place to put the alligator clip on the main red white wire. The other would go on the positive coil terminal. Then I would put a coin in and see if it the add credits coil fires correct?

First and foremost, I appreciate your help and patience with me. Fixing this EM has been an exercise in patience. A learning experience for sure. I am enjoying learning the schematics and how these things work, it’s cool.
I understand the schematics and the jumper cable concept, I am an engineer by trade, so good with this kind of stuff, although not an electrical engineer obviously.... I have a couple 2-3 foot jumpers with insulated alligator clips, and I understand to put one clip on the orange green side of the coil, but where EXACTLY do I put the other end of the jumper? Do I trace the wire back to the main red white wire and clip on to an exposed section of the red white and then power up and drop a coin in? I am kind of struggling with where exactly to put the other end of the jumper in order to make it work. This is a nit picky item and I can put credits on the machine manually, but I spent so much time on it now, that I want to get it running perfectly. I disassembled and rebuilt the credit wheel mechanism already so it’s working well mechanically, and again it works fine taking credits off. I cleaned the coin slot plugs as well. Again, thanks for your help and patience.

Yep. W relay fires in both slots. Checked the coil and it fires. Checked the motor switches and they all are cleaned and appear to be closed. I guess I jumper the Jones plugs now to see if it is them? Checked all the different Jones plugs and the 1st coin chute plug appears to be working, when I put it in there and drop a coin it takes a credit off and restarts. So I guess I am down to the 2nd chute adjustment will try and jumper over it.

Hey I built a long jumper and just went through the schematic.....it ended up being the switch on the W relay. So the machine now works completely correct! Thanks everyone. Wahoo.
I owe you all a beer, and now on to the final problem in my collection a switch matrix problem on fish tales. Thanks again.