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Scoring and GI issues - Zaccaria Moon Flight (1976 / EM)

Xephlon

Registered
5Years
Joined
Aug 7, 2018
Messages
38
Location
Redditch, England
Hey all,

I'm having some issues with my pinball's scoring and illumination. I recently did a rebuild of the playfield for my machine and I repaired all issues I saw at the time. Upon reinstalling it into the cabinet I now find that the score motor has gone crazy. This was not an issue before. I have searched for any closed rollovers or target switches but everything seems fine. The motor will energize the 50k points relay and the machine will just count up forever. Any ideas?

I am also having some funny issues with the illumination for the backbox. The 6v line off the transformer reads 6v ± 1v and I read continuity to the bulb holders in the backbox even after removing all bulbs and the playfield and coin door bulbs. I cleaned the fuse holder and putting a single bulb in the backbox got it to work! I put the rest in and it stopped working. The multimeter was reading crazy voltages during gameplay (score motor and coils firing) from 0v to 18v. After cleaning the fuse holder the playfield doesn't illuminate either but the playfield lights use a separate fuse line.

If anyone can assist with my issues then I'd be very grateful.

Thanks,
Josh

ipdb: https://www.ipdb.org/machine.cgi?id=1626
Schematics: https://www.ipdb.org/files/1626/Zaccaria_1976_Moon_Flight_Schematics.pdf
 
The motor will energize the 50k points relay and the machine will just count up forever. Any ideas?
It could be the other way round, if something is sticking on the 50K RE it would continually run the score motor via the yellow/green-red switch

The playfield lighting circuit is different to the backbox and isolated via the Lock RE, is that energised?

Is the normal switch on, credit, game startup process working normally?
 
So I checked the yellow / green-red switch on the 50K relay. Whilst it was definitely open I was reading continuity on my multimeter. I looked at the schematic and insulated every yellow / green-red switch that powers the motor including the 50K relay. The motor is still powered and despite insulating every relay on the schematic it continues to rotate.

Even with the lock relay energized the lamps don't light up. Coin door and backbox lamps have never worked properly and I think they're meant to work without the lock relay as they are wired straight onto the 6v and common terminals of the transformer. I am certain the fuses are good.

The startup sequence seems pretty normal. Whilst the start button doesn't begin the startup sequence (worked in Freeplay mode before things went crazy) adding a token through the coin door seems to energize the relevant relays and reset the score reels to 0.

I can't even comprehend how the motor runs with all its power switches being insulated and the lamps that are directly wired to the transformer fail to turn on (only sometimes, worked when I first got the machine and for one play session when I cleaned the fuse holder). Maybe the machine is haunted haha. Thanks for the help astyy
 
Whilst it was definitely open I was reading continuity on my multimeter.
I'm not sure that is so useful on an EM as you could well be reading back round through the transformer, jumper leads and slips of paper :thumbs:

The motor is still powered and despite insulating every relay on the schematic it continues to rotate.
When does the motor start running?
 
I'm not sure that is so useful on an EM as you could well be reading back round through the transformer, jumper leads and slips of paper :thumbs:
Ah of course. That was a silly mistake. Still, I'm pretty certain all relays are insulated. Only the O.R.B.I.T relay on the schematic that I couldn't find

When does the motor start running?
After putting the playfield back in the motor would only run after hitting a target or rollover. It would stop normally after the startup process. Now the motor will run as soon as power is supplied to the transformer.
 
Now the motor will run as soon as power is supplied to the transformer.
That is something solid we can concentrate on as somewhat fundamental to the machines operation. The 24V circuit is closing to the motor "somewhere" on the G-R wire, so I think you should inspect and isolate each of the TWELVE Y / G-R switches shown below (note 4x ADVANCE MODULE 15G on schematic), the SEQ ORBIT RE is marked on the schematic as 300K PT RE too, so perhaps that's how it's labelled in the machine. When you find the switches check for shorts on the wire end soldering and tabs.

When "power is supplied to the transformer" what other Relays are energised? You mentioned the 50K PT RE (that would normally run the motor) perhaps isolate that on the SPECIAL EXTRA BALL RE switch V-W / B-G whilst we try and sort the motor.

The fact you've done "work" on this means we're not necessarily working from plans, I'm not ignoring the playfield and 18V(?) Backbox lighting issues but sometimes resolving one issue at a time has a waterfall effect and is the simplest approach.

Btw, I'm not the most experienced so may not be leading you most efficiently, others may well chip in too :thumbs:


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I would clean the Jones plugs at the rear of the cabinet for the playfield connection (I presume you unplugged it when you removed the playfield). I would also clean any other Jones plugs while you are there (backbox in particular). Use a wire brush or sandpaper to get the connectors clean.

If that doesn't help much then work your way through this:
http://www.pinrepair.com/em/index.htm
 
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you should inspect and isolate each of the TWELVE Y / G-R switches
I found the O.R.B.I.T relay and isolated the G-R switch. All 12 switches were insulated with paper and it still worked. Just to make sure I used some cereal box cardboard to ensure the switches weren't arcing. No joy... I checked all solder tabs and whilst the motor reel switches look a bit cramped I didn't notice any contact between them. All relay's solder tabs are distant and isolated from eachotehr

When "power is supplied to the transformer" what other Relays are energised?
No relays are energized at all when the game is switched on. I disconnected every plug connector except for the mains input and the motor still worked, so the issue is definitely on the mainboard. Before the motor was on constantly the 50K relay would energize and stay on after scoring points. Now the motor runs regardless of the relays.

The fact you've done "work" on this means we're not necessarily working from plans
I haven't made any changes to the machine from how I received it. I noticed one of the previous owners fitted a replay counter on top of the total play counter but I haven't noticed any other changes. I only removed the playfield to depopulate it and fit a lexan playfield protector, however, I am now certain that the issue is based on the mainboard.

I would clean the Jones plugs at the rear of the cabinet for the playfield connection
I cleaned and buffed the playfield and backbox connectors to a shiny silver colour; just as clean as they would be out of the factory. The female plug sockets look a bit dull but I am doubtful that it would make a difference to the contact. I'll be sure to double check my connectors and fuse holders.


Thanks for the help you guys! If I can help you help me by sending pictures of anything then just ask. This is my first pin so my knowledge of them is pretty feeble.
 
Thanks for the help you guys! If I can help you help me by sending pictures of anything then just ask. This is my first pin so my knowledge of them is pretty feeble.
I think you're doing really well, putting up with my ramblings for a start, a lot on here fear the path of the EM :thumbs:

So if I understand this correctly, you have permanent connectivity when togged on from the transformer via the Y and G-R wires, when that should be normally open via 12 parrallel switches (ie an OR logic circuit). What about removing the 15A fuse for the 24V circuit (B-Y-W/Black wires), then (POWER OFF) you can buzz continuity with your DMM to your hearts content from the yellow wire lug on the transformer to the motor, that should be closed. With the fuse out you're not buzzing through the transformer. Then check across each switch in turn. I guess it's not necessarily one of the correct switches it could be shorting elsewhere.

Also may be interesting to see if the same occurs with the pf and bb unplugged in turn.

Also (2), I see this machine has a number of trip relays, it may be worth manually moving them to their alt position to observe results.
 
I removed the fuse to use my multimeter but I was still reading continuity on all switches. Because one of the live wires is making contact with common, I'm pretty sure they're all connected. Playfield and backbox are all unplugged. Still doesn't make a difference, unfortunately. With the trip relays, the trip will energise as soon as the latch's switches are closed. I'm unsure if this is normal or not because the motor is constantly running, but I believe the latch should energise and then the trip only energises after the game. Both exhibit the same behaviour.
 
I believe a constantly running motor is normally an indication that a zero switch on one of the backbox reels isn't closed or showing/registering as such (in other words the game thinks that all the reels are not showing zero and the motor keeps going until they do).
 
I think that the motor running when the score reels are not at 0 is when the reset relay is activated. I'll do some more poking around and see if I can crack this
 
Yes the Reset RE stack houses one of the 12 switches that can start the motor which you insulated to discount. The schematic shows 2 Reset Relays which is a tad confusing.
 
Looking at this schematic, have you also checked the outhole relay? next really carefully double check the switch that is on the score motor itself, the one on Index C - the one in a circle on the schematic above If that is not opening then the score motor will just turn and turn and turn. It's easy to get the wrong cam on the score motor, so make sure you are looking at the right switch. C is the toppermost one on the Index cam.

As @astyy says above, just go around checking continuity across all the above switches, one of them must be shorted linking G-R to Yellow. Even though you have isolated each of the switch leaves from each other with bits of cardboard, there could still be a short, e.g. a blob of solder dropped somewhere etc. You may have to start disconnecting each of them to rule them out - that's a pain to do
 
The schematic shows 2 Reset Relays which is a tad confusing.
I believe one (on the mainboard) is constantly energized when resetting to begin the reset process. This then closes the switch that allows the second reset relay (in the backbox) to pulse the score reels.

have you also checked the outhole relay?
Yes I have. I was sure to insulate the switch in the relay stack. I also insulated the switch at Index C. Whilst all switches on the motor look pretty cramped I don't think any of them are close enough to close.

You may have to start disconnecting each of them to rule them out - that's a pain to do
This sounds like fun... I may remove the mainboard from the cabinet to get a better view. Thanks for all the help!
 
Yep, I think you're right. Time to lift out the main board and do some serious investigative work.
Hopefully with the motor board out you can much better eyeball, what's keeping the motor running, it's a simple circuit then take it from there. As a side note, my Bally EM is super cool, as the canopy glass, pf and motor board all hinge up to top of cabinet level and you can run the machine in that position for boss trouble shooting :thumbs:

For me desoldering lots of switches would be a last resort, but if you must choose that route I'd choose a switch to bisect the circuit, test which side is closed, then repeat. Less tampering that way.
 
For me desoldering lots of switches would be a last resort, but if you must choose that route I'd choose a switch to bisect the circuit, test which side is closed, then repeat. Less tampering that way.
Fantastic idea - the "binary chop" method!
 
And does the bonus count go down to zero or is it on zero (well 10,000) with all the orbit lights out?
Not too sure how the bonus circuit works but I'll have a look.

As a side note, my Bally EM is super cool, as the canopy glass, pf and motor board all hinge up to top of cabinet level
Very cool! Whilst Zaccaria made a great game their maintenance features consist of a wooden rod nailed into the side of the cabinet which can be used to prop up the playfield. I won't lie though, the artwork and game mechanics more than make up for it.

For me desoldering lots of switches would be a last resort, but if you must choose that route I'd choose a switch to bisect the circuit, test which side is closed, then repeat. Less tampering that way.
Okay I'll give that a shot. Hopefully I can come back this evening with some good news!
I really appreciate the help and it has been great to get so much good advice. Thanks guys :D
 
Almost identical to the scoring reel mechanism, normally a big square plate with clock like feeds on the backside of the playfield.
Oh ok I think I've seen it. There was a metal attachment screwed onto the reel to obscure the number when viewing through the backglass. I'll double check its all working
 
Under the playfield not in the back box behind the back glass. Although how you quoted that makes it sound like you've not been in the back box ýet. If that is the case then how do you know that the zero switches for each scoring reel are working correctly?
 
I have definitely been in the backbox. I was just a bit unsure of what I was looking for. I know what you mean now. There are two of those and I took one apart to clean and tune two days ago. I didn't know what it was but it was jammed.
 
I suspect that might be the cause of your problems.

So you can advance and reset the bonus count and orbit lights now you know what you are looking at..?
 
So you can advance and reset the bonus count and orbit lights now you know what you are looking at..?

Yes. Originally the game would run but I think the ORBIT feature was a bit weird. It wouldn't reset so you'd have a full ORBIT bonus from the get-go.

UPDATE:
I have successfully located the area causing the issue. After desoldering the switches from the motherboard, I found that the G-R wire on 'Advance Module No.2' is causing the issue. However, the switch is open and it is not the relay itself that is causing the issue. I will have to have a look at the schematics and see where the wire could be having issues.
 
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