Would appreciate any help with this. I have a Sonic Mars Trek that I've been working on for a while and I'm not sure what else to try to get it working correctly. The main problems I have is that the start button will not start a game. I can add credits with the coin switches and see that they are added to the credit reel. I can manually activate the relays on the relay board to get it to start a game and it will subtract a credit but the ball does not kick out from the trough to the shooter lane, and likely related to that the game will not detect a drain or a ball in either bonus outhole. I can manually activate the outhole relay and it will advance to the next ball and I can get through a game that way. Everything else on the playfield works and scores correctly and the reset relay will zero out all the score reels.

I can activate all the relays on the bottom board and on the bottom of the playfield and they seem to function as they should. I've cleaned the rivets and lubed all the stepper units and they move well.

Some other things I've noticed- I'm not sure why but occasionally after playing with the relays the start button has worked to start a game but I have the same issue with the outholes not activating and I'm not able to reproduce it consistently.

One final concern is that the bonus switches are slow to activate the stepper, meaning if a moving ball passes over a rollover switch too fast it won't fully activate the bonus step up. I can hear it initiate but it won't complete the step up unless the switch is held down for a second or two. Thinking that may be a switch gap issue on the score motor?

I can view the schematic at IPDB but don't have one on hand https://www.ipdb.org/files/1550/Sonic_1977_Mars_Trek_Schematic_Diagram_continuous.pdf

Sorry for the long post. Thank you for reading and for any help with this.

Thank you for that suggestion! I just checked the No. 1 and No. 2 coin relays, cleaned with a flexstone and made sure the movement was good. Activating these will both add 4 credits so they seem to be working. There is a relay next to it called Coin Set up Relay, activating this by hand does not have any effect. I should add that on a couple occasions when activating the Reset Relay I noticed this coin set up relay firing and it caught my attention because it was sparking a bit, I haven't noticed it do that again and it also doesn't activate with the reset relay anymore.

Something new I've noticed, with the credit reel at 0 if I activate the reset relay I can then push the start button and it will add another player but it still won't start a game.

Ha I didn't notice there was a 3rd coin relay on the other side of the board. Went through and did the same thing to that one, this one does not add credits to the reel but does cause the score motor to spin around once.

Does your coin door coil pull in when you power on the machine? I've noticed mine does not do that and when adding credits I see the coil do a very weak pulse which is not enough to activate the lockout. Wondering if I have a bad coil there that's causing some of the issues. Thanks again for your suggestions, very much appreciated.

Thank you for the schematic clipping! Just ordered some alligator clip jumper wires so I'll be able to test that later this week and will study those links so I have an idea of what to do, I'm brand new to schematics and jumpers so I have a lot to learn ha. Thanks again for taking the time to respond.

Thanks a lot for confirming that, I had a feeling mine wasn't working right. Will try to figure out why it's acting up.

Got the jumper wires. I read all the links you sent but it's still a bit confusing to me. Am I jumping the credit button to the credit relay, where you've written in red on the schematic? I went ahead and tried that with one clip on the white/orange wire lug of the credit button to the black wire on the credit relay coil. I have a feeling I'm reading it wrong as that didn't have any effect.

Thanks for the quick response. I do see the five switches now. I'm sure using jumpers will click eventually but for now I'll start by visually inspecting each switch in the circuit to see if there's anything that could be causing an issue. I appreciate the help with this!

Thank you for this. All the switches I've looked at meet this criteria and all the relays activate when pushed by hand.

I was able to jump the reset relay to the credit button and that did start up a 1 player game, if left on there it would add 4 players. Does this mean the problem lies between these? I see a switch marked IND-A on the schematic. Unsure what that is referring to though.
Also I noticed when it starts a game the trough outhole will fire but in a game all outholes are inactive, one problem at a time haha.

Sorry I left that out, originally I was connecting Orange/Green from the reset relay switch to the White/Orange of the credit button, this would instantly start up a new game without me pressing the credit button. I see I had that wrong and tried it the correct way-

This was correct! Pressing the credit button with the jumper installed started up a new game and subtracted one credit. Going to take a good look at Index-A on the score motor and see if anything stands out. Thank you again for all your help, very much appreciated.

Good news @howardr! You were spot on with helping me track down the problem. After looking at INDEX-A and spinning the motor a few times I noticed that the top switch contact was too high and never made contact with the one below it. A quick adjustment and the credit button works works every time! Not only that it fixed all the other problems I wrote in my first post. Thanks again for the introduction to schematics and jumper wires, it helped me out a lot here and I'm sure will help in the future as well.

I do have a new issue that seems to be related to the bonus collect. Almost every time the ball drains or lands in the collect bonus outhole on the playfield it will sit there while the bonus unit steps down to 0 then up one and back to 0 in a loop and it won't kick the ball out. If I pull the ball out it will eventually stop. I noticed that the bonus stepper arms don't always make a nice centered contact with the rivets, like it's almost touching two rivets at the same time. Do you think this could be the problem and is there a way to adjust these stepper arms?

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Thank you for these instructions, didn't know you could rotate the contact board like that. I turned the board just enough so now the rivets are all centered now. Much appreciated!

I was hopeful that would fix the bonus collect issue but it unfortunately persists. I shot a couple videos, one of the playfield side and one of the bonus stepper while its happening. It seems like half the time the bonus collect saucer works as it should where it steps down and ejects the ball and relights the 10000 bonus light. Half the time it sits in that loop until eventually ejecting the ball. There has been a few times where after ejecting the ball the 20k bonus light is lit rather than the 10k and it will jump to the next ball without it ever draining.

Still working on this but not sure if I should be focusing on the bonus unit or the score motor for this issue. The schematic gets a little confusing when it comes to the bonus collect/right eject saucer and I'm having a hard time figuring out where to look. Any suggestions appreciated! Game is playable except for this last issue, getting close.

Thank you HowardR for the schematic highlight.
I jumpered from the Brown/Red wire on the score motor to the White/Green on the Auxiliary eject relay. With the jumper the bonus collect works much better and will kick the ball out from the right saucer without the reset loop although it will sometimes kick the ball out while the bonus is still counting down. Also it will fire the eject relay anytime bonus is advanced. Still have the occasional reset loop when the ball drains but seems to be gone from the collect bonus saucer. Does this indicate an issue with the relay that was jumped?

Looks like all the contacts are working as they should. I could try adjusting the gaps closer so they have better push on the short blades but as of now they move when the relay is pulled in. I also cleaned the contacts and tightened the switch stack. Not great pics but maybe you'll see something I'm missing. First pic is the relay not pulled in, second pic is pushing in the relay latch. Thanks for the quick response to my last question!

To add to my confusion, there is a relay directly underneath the Auxiliary eject called Right Eject Relay but those contacts all seem to be working as well.

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On the machine there are these eject relays. Looks like the schematics differs a bit in naming of the Auxiliary R. Eject Relay but safe to say it's the same one?

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Gotcha, I'll check out that switch on the aux eject relay.

I believe this is the correct switch on the Auxiliary Eject Relay, White/Green and Brown/Red seen at the top. Visually it looks ok, switch opens and closes like normal.

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Sorry to bump this so much. Still trying to find a solution for the bonus countdown loop described in post #18 where the ball enters the bonus collect saucer or the trough and bonus countdown will work as expected counting down to 0 then back up to 1000 and instead of ejecting the ball it will cycle back to 0 and then 1000 for around 10-15 seconds before eventually ejecting the ball.

I looked at the score motor again while spinning it and all switches there seem ok. All relay switches seem good too so not sure where to look to track this issue down. Thanks to the help from the two posters in this thread the game is playable and the bonus countdown loop only effects it for a short time.

Sorry to go so long without updating, I really appreciate everyone's suggestions. This issue was frustrating and I couldnt locate the problem so I took a break for a bit. After spending more time with it I can see that both saucers and the outhole behave the same way though it was worse at the bonus collect right saucer. A ball in the top saucer will occasionally sit while the motor turns before being ejected and now a ball in the outhole will not always kick out. Apologies in advance for all the videos, hopefully with more eyes on it the issues can be narrowed down.

Activating the right saucer-

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Video of the score motor while activating right saucer-

Also I have an issue that affects the Special that I was not aware of before, probably because I never achieved it. When special is lit after spelling "Mars Trek" one of the chime coils locks on and the score motor spins until the ball is drained. I have a video of that also-

I'm not sure if these are all related but it makes it difficult to locate the problem as I'm not sure if I should concentrate on the motor or the relays, I've done both and don't see anything that stands out.

Hey Dave, thanks for asking! I appreciate your input on the game last night. Thanks also to the coaches who offered helpful advice. The Special issue that caused the score motor to spin is now solved. The Special relay was stuck and after adjusting it works every time now. Also got the info I needed on why the slingshots weren't scoring, just had to adjust the scoring switches under the playfield and they work great now.

As for the trough and bonus saucer not always ejecting, I got a lot of good advice on where to look and what to focus on but unfortunately I wasn't able to make any more progress there. We looked at the score motor switch stack that is linked to both eject relays and everything looked good there so I think I can rule out the score motor. Also looked at the bonus stepper unit and adjusted those switches so those are good and I think I can rule that out.

That leaves me looking at the associated relays, I played around with those and found that the right saucer eject is activated by the Auxiliary Eject Relay which if I activate by hand does not always cause the coil to fire unless I hold it in for an extra second. It seems like the timing is off and the relay isn't staying engaged long enough to fire the coil.

In this video I'm activating the saucer switch while showing the relays. You can see that the Aux R eject for the most part doesn't fire unless I hold in the relay for an extra moment. The last part of the video shows the score motor while first activating the saucer switch and then just activating the Aux R Eject relay which fires every time the score motor passes a "valley" on the cog.

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Thank you for the clear instructions, just had a look at that. With the score motor in service mode, closing the saucer switch causes the Right Eject Relay and the Auxiliary Eject Relay to hold. Turning the score motor a bit causes the Right Eject Relay to disengage before the switch stack drops. When the switch stack drops is when the Aux R Relay hold disengages. Several times while spinning the score motor, I could get the saucer eject to fire repeatedly when the switch stack dropped, when this happened the Aux Eject Relay was holding. Many times the Aux Eject Relay would lose its hold before the switch stack dropped. Currently I have the score motor in the position where the saucer will fire when the Auxiliary Eject Relay is engaged.

Thanks for your help and patience, I'm sure I'm making it more confusing than it is but I hope this info helps to understand where the problem might be.

Dave, you're the man! I really gave the top blade a closer look and you were right on about a weak connection. It looked like it was making contact but I bent the blade a little to minimize the gap for a stronger connection. The ball ejects from the outhole and saucers every time without delay, so great to see! I also checked all the other top blades and did small adjustments if it looked like those had weak connections.

This machine was my first EM and project pin, it was a mess when I bought it but now almost two years later, with lots of help from this community the game is up and running 100%.

Your help and the repair clinic really helped me to understand how the score motor and relay hold circuits work and how to locate score motor switches and their relays on the schematic which will definitely help with future projects.

Thanks for all your help with this. I really appreciate you sharing your knowledge to get this game working again. Thanks as well to everyone who offered advice in this thread, couldn't have done it without the help I received here.
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