Gottlieb Solved Sky Jump (Gottlieb, 1974) First Post - Problem with ball feed mechanism

[CML828]

This is my first post. Cool forum. I have an old Gottleib "Sky Jump" machine (photo attached), and the machine works well except it has an ongoing problem with the ball feeder. Once the ball drains into the drain area at the front of the machine, it has trouble getting fed back up into the manual "plunger" device that will send the ball back out into the machine (into play). So the ball goes into the drain, then the scoring adds up, then I am supposed to push the main silver button on the front of the machine to get the ball fed electronically back up to the plunger area. I hear the mechanism operating (ker-chunk!), and it sounds like it has before (when the feeder was working), but the ball does not materialize. A few times I have picked up the machine a little and tilted it to the right (towards the plunger side), and then pushed the silver button and the ball has come up to the plunger. So maybe the ball is not sitting correctly in the feed mechanism once it drains, or maybe the feed mechanism is bad somehow. I suppose that this may be a common problem with pinball machines, but since I am new to this I wanted to see if someone could direct me to instructions to repair it. I think I know already how to get into the machine (how to open it up, etc). I believe that I open the front cover (coin area main box), then I reach into that area and find the lever that pulls down to free the front strip that sits in front of the main glass piece. Once that strip is removed, then I can slide the glass out and get access to all. I need insrtuctions from there to get into and check out the ball feeder mechanism. Thanks alot everyone. After I get the Gottlieb machine done I will check out the other machine I have (a Bally machine) to see what is wrong with that and will likely be posting questions about that machine as well. Cheers. Chris

 

[DaveBonds]

Once you remove the glass lock bar and remove the playfield glass, there is a big lock bar inside of the cabinet that unlocks the playfield itself. If you can see through the coin door, you should be able to see a horizontal bar that spans the entire cabinet. If you pull back on it, it should lift and release the front of the playfield, so you can lift the playfield and prop it up with the rod on the right. Be sure that the prop rod is in from the edge at least an inch, where you set it. It should stop against itself and you should see marking where it was set, prior to. Just be sure that it's in from the edge at least one inch, even if the marks aren't.

You may want to check the level of your machine and correct it as needed. If the ball chute slope is too shallow, it may not be returning the ball properly because of that.

 

[CML828]

Hi there. Thanks for the reply. The machine is set for unlimited play. No coins are needed to get the ball to return. So I do not think that the level of the machine is the problem. Also, the machine did work correctly for a while (the ball fed back up to the plunger area each time as it should after it drained). I used the machine maybe 10 times and all worked well, but after that the ball would not come back up normally. I have been told that it may be the outhole switch for the outhole operation. If the switch is dirty it could be limiting the voltage running through it and not providing enough power to operate the outhole mechanism well enough to eject the ball up to the plunger area. I have been instructed on where in the machine to look for the switch to clean it to hopefully get it to work properly, but your post on the horizontal bar that I have to lift to get the play surface up in the air is helpful. Was not aware of that. I will see the machine again this coming weekend and will check it out then and will contact you back with my results. I assume that the outhole area (where the ball drains at the end of play) will be accessable after I get the playing surface unlatched and get it propped up, so I can inspect that area to see if there is any problem mechanically there. If not, then I will locate and clean the outhole switch (the "O" relay). Thanks again for the input. I will post back.

 

[DaveBonds]

Everything should be accessable. If the ball is simply not triggering the ball return hammer coil, it's most definitely a switch issue, either at the wire rollover switch in the out hole or at the relay that it triggers. I've discovered that in a lot of cases, the rollover wire itself becomes too low in the playfield from age and use and stops giving the leaf stack switch full contact. Sometimes it's necessary to adjust the rollover wire itself if the gap on the leaf contacts looks close.

The older Williams and Bally games just have a drop in playfield, but the Gottlieb cabinets had a lock bar holding them down. The playfield lock bar should be just behind the coin tray and has a reasonable amount of spring tension on it, unlike the glass lock bar lever up at the top of the coin door opening. You will also need to pull the lock bar toward the front of the cabinet again to get the playfield back down into the cabinet when you are done.

 

[CML828]

Thanks a ton Dave. Excellent info. What is actually happening is that the ball drains and then I push the button on the front of the machine to re-load the ball from the outhole to the plunger area, and the outhole motor is firing but the ball is not coming up to the plunger. So I think that it may be a lack of power to the outhole eject mechanism, and therefore the switch operating the outhole (the "O" relay) is not giving enough juice to get the ball out. So I was going to clean the switch and see if that does it. I can also inspect the outhole mechanism, and your info about what to look for there (type of mechanism and how it activates the relay) is very helpful. Any other ideas/advice? Again, each time I push the button on the front of the machine, the outhole eject motor is firing. The outhole eject was working fine a few weeks ago, and it always provided the ball back to the plunger, but it has stopped doing that. You don't happen to have a schematic for the guts of this machine to find that "O" relay on this machine, do you?

 

[DaveBonds]

If it's like a flipper coil, they have doubled voltage through the use of two positive feed lines and a ground wire. You can stack volts, unlike amps, when two sources of voltage power are used. Weak flipper coils are usually always subtracted one of the wire leads. Most of the time, the shoddy soldering fails, from the flipper unit itself banging around, so it loses half of the voltage source and is half as strong.

If you can hear the eject coil operating, can you hear the ball climbing the guide ramp/ hill and falling back into the coil hammer? if so, it is probably a weak coil. If not, it could be that the ball is hanging up before reaching the coil, but from what I read, you were saying that it had the ability if you nudged or tilted the cabinet, so it's likely a weak coil. The letter O relay that runs it is probably doing it's job, because it is actually acivating something, but it's likely not sending full voltage through both of the wires, if it is a three wire coil. I would bet that the leaf switch stack on that O relay has two contact leaf points, for duplicated voltage.

With the info you just gave me, I'm also willing to bet that one of those contact points is fouled to the point of not making any contact. If you were to use a multimeter set to check continuity, I'll bet that you aren't getting any on the two leaf contacts that run one of the power wires to that coil, when the two leaf points touch.

The first place that I would check would be the coil itself, because it moves a lot more than the relay and it is more likely to have a broken or weak soldered wire on it fail than the wires at the relay itself. The second place I would check would be the "O" relay and clean the contacts on it.

I don't have the schematic for that machine, but the relay is labeled on a long paper sticker, laid down on the board that the rail of relays is attached to. The relays on Gottlieb cabinets are usually attached to the rail with a hair pin that pulls out of a hole, so you can move it around freely, while it's attached to the wiring, to gain easier access to the contact points for maintenance.

The quickest way to locate that relay, if your labels are gone or difficult to read is to manually trigger that wire rollover switch that activates the eject coil and look for a moving switch stack on the rail. You'll be able to see it easily, just watch where you trigger it on the wire rollover switch, the first time you trip it, so you don't get bit by the coil firing. After you've seen which switch stack moves and you've located that relay/ switch stack, note where it is exactly by counting relay units from the closest end on the rail of them and unplug the machine before cleaning points or disconnecting the unit from the rail, if you decide to partially remove the relay from the mounting rail bracket.

 

[CML828]

SOME NEW INFO. I got the back of the machine open got the glass out and checked out the guts. The outhole relay looks like it is working fine, and the swing arm next to the outhole that sweeps the drained ball up the channel to the plunger area seems to be firing as well. BUT, I noticed that the TILT LIGHT is lit on the backglass, and it is on all the time. And I am guessing that this is the reason that the outhole mechansism is not being allowed to fire to send the ball up to the plunger. I looked at the tilt mechanism (it is a plumb bob type), and it seems to look ok, not touching the sides of the swivel (so it should not be activated). However, in looking at the manual for the machine (which I found inside, very lucky for me), I see that it has 3 tilt mechanisms. Anyway, now that I have seen the tilt light on, how do I get it to go off so that the outhole might operate again? I have moved the machine around a small bit to see if it will go out (no luck), I have moved the plumb bob around to see if that works (no luck), so I thought that I would get back on with you at Pinball Nirvana again to tell you of my (lack of) progress and see if you had any ideas. I will not see the machine again for 2 weeks or so, so I am hopeful that this next time I will hav all I need to get it up and running. Sorry about my prior posts above about the outhole being the problem that created a bit of a wild goose chase here.

 

[DaveBonds]

Turn the game on and watch the Tilt relay. If the relay moves and stays on, one of the three tilt switches is triggering the relay. If nothing moves when you go to start the game, the leaf contact switch that the relay runs is likely fouled up or has a gap.

The "T" relay is usually the Tilt relay. You might try cleaning the leaf switch contacts on it so that they are making constant contact with the relay off. If that connection is broken, it will activate the Tilt mode and will keep the ball gate coil from activating the gate.

 

[CML828]

Thanks Dave. I will try it. Will get back to you in 1-3 weeks, after I see the machine again and get to work on it. Can I run the machine (turn it on, ect) with the playfield in the upright position? In other words, if I have the front coin door open and the playfield glass is removed and the playfield itself is tilted up against the backglass, will the machine still turn on as normal (so that I can be observing the T relay inside the machine at the time that I actually switch the machine on)? And as to the tilt switches, I only saw one pendulum type tilt switch on the left side (near the front of the cabinet) when I looked into the machine originally. Where are the other 2 tilt sensors? Are they pendulums too? Give me some info on those other 2 switches (locations, type of switch) if you could, so if I clean the leaf switch on the T relay and it turns out not to be the problem then I can look into the other switches while I am there. Hope to report next time that the machine is up and running.

 

[DaveBonds]

The box above the bob tilt switch is a percentage/ playfield grade switch. It's just a 1" steel ball that rolls in a track and either makes contact with the leaf switch that is mounted near the plum bob or does not, depending on if it is adjusted properly or not, or if it was adjusted when the cabinet was set up. The ball inside, if it's still there, shouldn't be contacting the leaf switch.

There is another on the playfield itself that is a simple leaf switch with
a weight on the end of it that should be open at all times, unless triggered. You should be able to lift the field without tripping it, if you're careful or at least reset the game with it up after you're done moving the playfield to examine it with the machine on.

The third one could either be down on the main board, somewhere near the drive/ reset motor. Any leaf switch that you see with a weight disc on the end is a tilt switch. There is also a slam switch on the door that you can look at, that will give you an idea of what the others look like. That switch should be in the closed position normally.

If the T relay is turned on with the game start, start looking for the tilt switches in the above suggested areas.

When you check the game in the normal running mode, when it triggers the tilt light, try turning the machine off and on with something that is not conductive between each of the tilt switch contacts, like a popsicle stick or something and put the game through an on/ off / start cycle, each time you're testing each switch like this, one at a time. You should be able to find the switch that is causing the tilt mode to trigger if you find each switch and test them individually.

I can't find any good pictures online of the inside of your game, but the switches are pretty obvious. They look like the weighted leaf slam switch on the inside of the coin door and are a single contact switch that are not connected to any mechanical devices and usually only have two or three wires connected to them.

 

[CML828]

Thanks for the post Dave. I do recall seeing the tilt switch #2 (the 1" ball running in the metal track on the left front of the inside cabinet area), and I thought that it was just a place for a spare ball to be held in case the first ball was lost or something. Did not know that that was tilt switch #2! And there was a small piece of paper/cloth at the end of the track that was causing that 1" ball not to make contact with the end of the track. The end of that track must be where the 2nd tilt contact switch is. So I removed the paper, as I thought that it was just a stray piece of material. So now the 1" ball must be making contact with that 2nd tilt switch and causing the machine not to allow the outhole mechanism to fire. Let me get back into the machine in a few weeks and I will reset things and see if that does it. I am excited to finally whip this thing. Hope it works. Cudos to you and Pinball Nirvana!

 

[CML828]

Hi Dave. I just got a look at the SkyJump EM machine again this weekend, and I fixed it. It was the tilt mechanism with the roller ball. When I put the small cloth back in between the roller ball, such that the roller ball no longer made contact with the end of the channel it rides in, the tilt switch light on the backglass went out, and the ball feed mechanism (the outhole) began to work normally. Thanks for all your input. Viva pinball nirvana!