Almost ALWAYS ground (aka GND).
It's useful to have aligator clips on the black lead of your DMM; so you can clip it to GND while you probe the other test points.

Time to break out PinWiki for troubleshooting tips.
https://pinwiki.com/wiki/index.php?title=Williams_WPC#Game_resets

You need to heat it up to bend without it breaking..

Thank you!

After reading through all that and not yet messed with trying to fix my machine, I'm guessing 90% it is the CPU board not being properly grounded... I will mount it firmly as I'm sure I didn't attach it properly as per this guide. I have a whole list of stuff to keep me busy if that doesn't work.

Thanks!

I'm seeing voltage change when I test the opto receiver on the cannon when I block the opto. 16 opto board has a red light on it. Board looks pristine. Basically new so It has apparently been replaced at some point by the Previous owner.

Also not getting any readings on the eddy sensors on the outlanes. Don't think this is related though..

Yes this was from my restoration archive; pictures were taken of everything, so I could put it all back together when I was done cleaning and polishing everything.

MezelMods used to make some 3dprinted "stack" brackets which would keep the switches square.
I don't know if they still make them; or if they would work in the application.

Coin Mechs are missing in that coin door; so yeah.

Nope. I'm not sure there is even a lamp there... nor would you want to be "shopping" that lamp after it "blew".
If I were going to do it; I would try some matrix led strips from Comet in that area.

Alright, having opto issues and finally decided it's time to try troubleshooting this legitimately. I played some games trying to get it to fail and have noticed a trend of the game deciding it's a good time to "Launch a probe" in the right gun...which is rather unusual.

I'd done final frontier and was working on the second round of borg locks. Had 2 locked, started Rescue mission, hit a couple targets and then hit the ball into the neutral zone. It for some reason counted it as my third lock. Neutral zone lock wasn't lit, and it is working, I went back to verify. Playing the mode like normal, losing a ball, and then it kicks a ball to the right gun and tells me to launch a probe right in the middle of multi-ball.

I've also gotten the balls confused in non-multi ball modes but usually upon exit with fast ball drains. EX. Ferengi when at 3 balls and lose two simultaneously. Sometimes when hitting the neutral zone but not activating the target it seems to spit a ball out the left VUK but not after listening the ball make it all the way through the subway. I suspect my issue must be related to the left side subway sometimes not properly counting. Though it's hard to keep a mental model of where the balls are.

I tried some of the obvious things. Looking to get more advanced. I've wiggled connectors in switch test on all trough connectors, no rogue readings. Pounded around the flippers, VUKs, Neutral zone area and no rogue readings there either. Used a plastic tool to interrupt all subway optos, and trough optos, all seem fine. Ran both the left and right subway diverter tests and the worked as expected.

Any advice on what I should check next?

I think I fixed it this time. Posting in hopes it helps some random internet stranger years down the road.

I firmly grounded all my boards. All seemed good, then had same random issues of motors and vuks going off during game. Reseated all connectors, same thing. I entered the Solenoid test and found I could stimulate the symptoms if I made the knocker go off. Traced it back with a multimeter, couldn't find the issue. Finally realized that tapping the backbox caused the issues. From here, I heard a buzzing after I tapped it, and located it as best I could to fuse F116 (its hard to pinpoint a sound in a backbox). Looked at the manual. There was a fast blow in there where the manual calls for a slow blow. I took out the old fuse, tightened down the fuse conenctors (bent them in a little), but a new 3 amp slow blow fuse in F116 and... buzzing stopped. I am guessing some of the wires plugged in backwards you all helped me with previously had caused some partial break in that fuse. Game works normally now. I can smack the backbox and it works fine.

I think I got my Star Trek Back!

I only say 'think" because this is the third time this week I've thought all was good. I guess I'll have to play some more... just to make sure

Thanks all.

The 3D bracket for these older Stern targets doesn't fit B/W targets. Normally you don't have the leaning issue with the B/W standup targets - Stern's targets were notorious and hence the after-market bracket was made, although now Stern have an anti-lean bracket on standups in all their new machines.

Working through a trough board opto issue. LED 7 emitter does not light up. I replaced with the Mouser part referenced in this thread. The LED does not glow in camera view like the others. Should this newer style? Just as I look at this photo again looks like the top side trace could be cracked. I’ll check continuity.

7149AD7F-2D31-449F-9564-0E0740AD2800 (resized).jpeg

Helps if you check top size continuity as well. Trace was broken.

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looks horrible and bet the back looks worse and needs re-soldering

Should have mentioned board was hacked to hell before I got it. Realized board was cracked/bent between LED 6 and 7. Yes, had to run a few jumpers to fix broken traces. Works now!

BDE75FB3-B67D-4004-8116-CDE682813DAB (resized).jpeg

Can finally start a game now that trough opto is fixed.

All 3 flippers are super weak. I cleaned the flipper board opto and checked and cleaned both EOS switches. Flipper coils only getting 20vDC. Trough kick out coil is at 70vDC. All other coils seem strong.

I just scored 13.2 billion with one buy in. I had 13 artifacts. I had eight for the first final frontier. I should’ve kept going and gone for Q continuum.

Check the BR on the fliptronics board - it gets 50V AC from the transformer (via J102 -> J104 on the Power Driver board) and converts to 50V DC specifically for the flipper coils

The other PF coils use a separate BR on the Power Driver board.

WPC Fliptronics (resized).JPG

Thanks for the help. Pulled the board. BR1 tests good with DMM in diode mode. Noticed C2 is completely missing (tied to BR). Normal? The manual shows this part is listed. A Google image search shows this board with and without C2. The board has a warranty sticker of 1997. Possible this is a replacement board from a different game that didn’t need C2, but STTNG does?
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I've seen that missing cap on several B/W games I have. I install one when I get a new game. I guess its not really needed, but why not install it.

I too have watched the balls to keep count of where they're going to figure out my opto issues. I have found one issue with trough. I've seen balls enter it and not be counted as being there. They just don't seem to be rolling smoothly. I've ordered the newer designed one from Mantis to hopefully eliminate that part of the issue. My playfield optos seem to be working for the moment, but I sear my I had an issue with my subway diverter a while back which seems to have stopped being a problem for the moment. Hope that helps a little...

FIXED! Chris H. Suggested to look at J105. Sure enough o had it upside down (key is in the middle of 5 pins). Flipped it around and good to go! Should be on the left side.

B2263956-728F-45AA-880B-2F1B83D4F896 (resized).jpeg

Sttng owners, Couple of questions.

Powder coat black or stay with original stainless steel? I know it’s an opinions but is there a consensus?

Is the Star Trek logo on the speaker panel, the original speaker panel or a mod? In any case where can I get it.

That's probably where the jumpers go for configuring 115 or 230 volts AC primary on the transformer. It should show on the schematic detailed information.

What kind of issues related to thickness?

That's a shame.

You are actually missing the voltage selector harness, whoever did this lacked the skill, knowledge, or tools required to move the voltage selector jumpers in in the existing harnesses.
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How did you figure they weren't rolling smoothly? I don't think I've had that issue. My problem is a lot of times the kicker into the launch lane often has the ball fall right back in the trough. It sometimes works fine, but other times can fail 3 times before it finally stays/auto launches

I would watch the ball roll into the outhole, and nothing happened in the game, as if the ball was still in play. I'd give it a shake and then it would register in the trough. I haven't been able to recreate the other opto issues I was having, so all good for now...

You are not missing anything. It's been explained to you already. It's only used to select input (wall) voltages. Your game is a re-import. It was wired for 240VAC. Whoever brought it back to North America didn't have the tools(or patience) to remove the pins and re-wire the connector properly so they just cut the wires and made some splices. Shitty ass job in all honesty. However there is nothing missing. I've seen many games like that. It's mostly laziness. Doing up the connector properly will make it look neater but will not give you anything more. there is no direct DC voltage anywhere from the transformer (that big metal thing in the cabinet that you called 'supply'). It's not a power supply. It's a simple transformer that just puts out different AC voltages for the different systems. It's the driver board that is the main power supply and it converts the AC into DC (12v and 5v are the important ones but there are other voltages for the coils(50VDC), flashers(20VDC), and the lamp matrix as well). There are other boards(fliptronics, DMD controller, etc) that convert AC to DC also but that's not important in this discussion.

Only the GI-OCD board uses a different connector in the cabinet. It taps into the 6.3VAC of the GI which no longer needs to feed the driverboard since the GI is run directly by the GI-OCD board. That's why you would have an unused connector left over in the cabinet. It's the 6.3vac link to the driverboard. I would leave it to make the mod reversible.

The LED-OCD does not hook up directly to AC power it just hooks up to the bottom right of the driverboard (lamp matrix) and DC power.

Accessories like ColorDMD and Pinsound come with splitters in order to tap into the 12v and 5v power.

The diagram that shows how that connector (with the cut wires) is wired was provided above. I certainly don't mean to be rude but if you are saying that you can't read a simple schematic like that one then IMHO you should definitely NOT be f#$%ing around with the wiring.

Hey Eric - just as an FYI as the guys have said you can set the input voltage depending upon your specific country using jumpers on the 9 pin connector from the transformer (later WPC models use a 12 pin connector on the power box to set the voltage). Anyway here are the 2 pinouts (on the board side of the connector) for 115V US and 230V EU for your reference https://pinwiki.com/wiki/index.php?title=Williams_WPC#Early_WPC_Transformers_.289_pin_connection.29 Note that what has been done on your machine is to cut and join the transformer wires before the 9 pin connector - this effectively is doing the same thing as the jumpers however it's hatchet job.

The only way you could change this back to looking normal would be to redo all the connections to the 9 pin connector and do the jumpers at the connector. It would shorten the leads from the transformer (you'd firstly check you have enough length) and you'd only do this if you were COMPLETELY comfortable with what you were doing and how the wires should be connected.

I believe what you mean is that the instructions say you can run off a 12v power supply in the cabinet. However the machines don't have that (other than the driver board). It's for people who decide to add an extra power supply - either 12v only or 12v and 5v to power all the add-ons. If you choose to buy an additional 12v power supply you can install it in the cabinet and drive your accessories such as Pinsound, ColorDMD, lit mods & buttons, etc. That's what I did in mine. Some on this thread believe it's heresy to add an additional 12v power supply and not needed. Others believe it is a sound move given that this machine in particular has a LOT of systems powered by 12v and adding even more is a strain on the power driver board. It just wasn't designed for all these additional power drains.

I did mine in a way that is totally reversible anyway. No harm done, no wires cut, no permanent mods.

Hmm...I have had ball drains occur and have the game think a ball was still in play. I just assumed that it must've been some other opto with the issue thinking a ball was still in a VUK, but I suppose if that were the case it would kick it out instead of going into a search. Maybe that is the source of my problems :/

Yeah give it a shake, could also enter switch test at that moment and see if the all the trough lights are appropriately lit for each ball...just got my trough today...should have it installed in a few days...its also has a cool feature that I wasn't aware of, it keeps the ball from entering the playfield with a sliding metal gate.

Cool! Can you take a pic further away so I can see how it ties in with rest of game and the scale of the items? Nice job!

I know sttng doesn’t have a fire button but I’m working on a virtual pinball cabinet that is themed for sttng.
Where possible everything is authentic, WPC wide body to spec, licensed art reproduction, reproduction speaker panel and grills, and in this case I would like to add a fire button that looks like it should be there (it would be usable for other games).

There is already a stl file on thingverse for the shape, but I have no creative juices.
Anyone up for helping me design a simple button, I already know I want the word “engage” on it, but following that I can’t find the right combination of graphics or words to make it nice.

I’ve got the star fleet insignia, enterprise-d, the word Star Trek, but maybe someone knows how to put it together better.

Here is a sample, super open to any ideas, hand written, whatever.

https://imgur.com/gallery/0gf6vpu

Alright...thinking I must not be having trough issues. Or at least it doesn't seem too likely to me. Here's my rationale:

I took a spare Wyze cam I had and plopped it under the playfield and played through to Borg multi-ball twice on two different games and didn't see any unusual behavior (unfortunately). My LEDs appear to be on, the emitter for ball 3 does look a little weak to me, but I didn't see them flicker at all during the entire couple games. No balls hung up on divots either. The only unusual cases are when the ball fails to pop out of the trough and make it into the shooter lane. The ball then makes it all the way to the start of the trough and rolls back down. It's possible that might be causing issues...I'm not ruling that out yet.

I've got a video and a night vision shot of the trough emitters with the camera:

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What problem do you have or are trying to solve?

In regards to the trough kickout failing occasionally, check the tip of the coil plunger is not worn or you may need to adjust the ball guide at the kickout hole that deflects the ball into the shooter lane - taking a slo-mo of the kickout and comparing one that fails to others that makes it can help work out what is happening.