I've started to have a problem where a ball goes into mission start scoop and instead of ending up at the left popper, it ends up in the right gun. Happens maybe 1 out of 10-15 balls. So once that happens the game just goes into ball search but doesn't kick it out of the right gun. nothing looks wrong in the subway. Tested all the switches and coils. Everything seems to work fine. Game is level. Anybody seen this before?

I suspect that one of the diverters has some play in it or is misadjusted.

Tighten the set screw(s) or readjust the resting position of the diverter arm that feeds to the right gun, so that it does not stick out into the subway when open. Also, make sure that it will close all the way to the opposite wall of the subway.

Thanks EEE! That diverter does have a little play, but doesn't seem like the problem as it doesn't stick into the subway (isn't even close) when open, and does seem to close perfectly. But maybe the play is problem. I'll look closer at that diverter.

Does the mission start when this happens? If not I think this is usually a problem where the opto at the Start Mission hole does not register when the ball enters, make sure it's clean, the subway is properly aligned and attached to the bottom and then test it with a ball in switch edge mode.

All the optos are working great. The game does start missions correctly during game play. It is a pretty clean game as it was completely disassembled a couple years ago and cleaned. Only a few hundred games since then. I did a lot of testing in switch test already. it will go to the R gun in switch test occasionally. So it really seems like it is just the ball wanting to go down that path occasionally and not the diverter. I guess I need to try and get a movie with my phone to figure it out.

This is a mechanical issues, the ball only goes where its directed to go, it takes the electrical action of a coil to direct the ball to anywhere other than the upper left VUK...in the absence of this electrical energy, only a mechanical force can keep the diverters closed and direct the ball to the right gun.

Only a failing opto in the right gun can cause the game to go into ball search at this point. No matter how clean the game is, it looks like you have multiple issues happening here.

STTNG Guru

I had problems with 2 of my ball diverters. One was sticking from old hard grease and the other the arm was out of adjustment. I made 2 videos dealing with each one. Maybe they will help with yours.

Hey Sam! Those video's are great. Very nice work. I think my issue is really just a bad solder joint. Not sure why I got a ball in the right gun a couple times. Now that isn't repeating, and I haven't been able to play the game for a while to test it out again.

Ok. New to the club. Game has been sitting in a Trekkie couple’s home since 1998. It’s dirty and I am hoping it cleans up well. Couple of questions:

1). See attached photo of what switch errors were present when I ran test. Doesn’t seem to be any rhyme or reason (column/row) that’s out. Can anyone give advice on what next step should be?

2) Balls. I used the menu button to release all balls. They all fired out and drained. Now, when I turn on the the game, it says “locating balls” and can’t find anything. No ball gets ejected into shooter lane. What next?

Good points of the game? Cabinet solid. DMD perfect. Cannons rotate and fire correctly. The game did fire up and played when at their house and when I got it here. Translite very good. I am excited to dial this in. Need some experienced STTNG folks here to guide me through

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Put up my best score last night after having owned the game for about a year and a half. Made it through 2 Final Frontiers and several Borg Multiballs. This was like a 30 minute game.

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Fixed! Wire broken off the left popper. Balls were hanging up and not being shot out. Game is playing! Woohooo!! Up next, switch errors from above and no backbox GI Light, no playfield flasher. Connectors, I am sure

If those switch errors were just showing up when you enter the service menu at least two (Borg Entry and Lock) of them probably have probably just not been triggered in a long time. In switch edge test push a ball or other object through there with the ship removed and if working it will clear the error. The left return lane is an Eddy sensor under the PF that may just need the pot adjusted on it and the trough may just be dirty or have a broken wire as well.

First off, WELCOME TO THE CLUB!!! You now have, what I consider to be, the best pinball ever made.

The only "real" issue I see here is that you have a bad trough opto, and in this game its a big problem. More than likely you either have a broken load resistor on your transmitter board, or a failed IR LED, these are very easy to fix. The opto board is subject to a lot of vibration...especially if its a first generation board without the anti-shock bushings.

I agree and I happen to have a video for that too.

I thought about that being a possibility. Where are those shots located? I know zilch about the gameplay of a TNG

Thanks! I am excited to have it. It’s always exciting to get a new game and discover all the things that make a game great.

How would one know if the opto board is without the anti-shock bushings?

Yuck. I'd have replaced those LEDs too... The crap brown color is a good indication of poor IR transmission as the Epoxy has "yellowed" due to emitting IR radiation for 30ish years. It's cheap at $0.74/ea insurance policy.

They should be this nice Blue/purple hue
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https://www.digikey.com/product-detail/en/on-semiconductor/QED223A4R0/QED223A4R0CT-ND/3907905

The main reason I mention this is I was having a lot of issues with my Optos and it wasn't until I went in an replaced every one of them with new ... did my flaky opto issues go away.

They are located in the Borg ship, top of the Delta ramp at the back of the game. This is one of the coolest shots ever put into a pinball machine, when that lock is lit and you drill the Delta ramp the diverter opens and the ball goes into the ship. It's best achieved as part of the "Picard Maneuver" which is the left loop (with spinner!) to the upper flipper and up the Delta ramp. Those two switches are under the ship, which can be removed fairly easily with the PF pulled out on the service rails. You could also start a game, manually knock down the drop to lit lock one, lock a ball, manually knock the drop down again to light the Borg lock and then chuck a ball up the ramp and into the ship. This would have the added benefit of testing the diverter assembly which can get gummed up and sticky over time.

@bobukcat....thanks for the detailed explanation. I’ll do those things when I get back to it. Here are some pics I took while cleaning it up.

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Epic!!

You can see them under the mounting screws. They are black runner grommets with metal sleeve in them, the sleeve allows you to securely tighten the board in place while still allowing the board some movement to absorb the shocks.

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Topside tear down...

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@Blitzburgh99... are you planning on doing some PopBumper maintenance on your machine before you put it back together?

I'd recommend a set of STNG Popcaps, EVOs, and some PopBumper Bodies if you are. I have some clear and red popskirts coming from Pinball.Center (hopefully ships on Monday)... so you might be interested on those as well.

Board experts, I've been having problems with F116 blowing randomly, can't seem to tie it to anything. I pulled the board assuming BR5 was bad, but it diode tested fine. BR1 on the other hand showed null for diagram 2 below, and over 1 volt when I reversed the leads. Just want to confirm this is tested properly before I order Bridges and caps.

Additionally BR4 has a previous repair, and was replaced with a 15amp instead of 35, but tests OK; should I replace this two while I have it on the bench?

Anything else to check before I pull the bridges?
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If BR5 was bad it should blow the immediately and all the time; since this is the only fuse for the entire 12VU circuit, you may have other issues going on that may not be tied to the PDB

That doesn't sound right; figure 1 and 2 should measure the same.

This is the BR for your flashers, it may not need to be 35A to operate and it could be that the only reason a 35A was used as it would have been cheaper to manufacture these boards using only one type of bridge rectifier vs sourcing multiple parts. Its up to you if you want to replace it, I probably would because it would annoy me knowing it was different.

Are your cannons moving slow? That’s a symptom I had when F116 was randomly blowing, and it was a bad leg on BR5. Might want to replace C30 (and BR5), though check voltage at test points and see how out of spec they are? Low voltage is another sign of flacky BRs and filter caps. Of course since BR1 is probably bad, start there, though if I recall correctly you can’t test it in circuit or maybe that’s BR2...

Also check your coin door keys and other stuff around the coin door to make sure nothing is shorting the circuit. Check display driver board and/colordmd for anything obvious shorting?

mavantix & Pin_Guy - Thanks for the responses. I checked voltages in attract mode, and TP1 and TP8, while not extremely low, aren't steady like the rest, so I'm thinking the caps have failed.

TP1 jumps 11.8 to 12.2
TP8 slowly goes between 15.5 & 18

Ordered some caps and bridges; wow does a Marco order add up quick!!
For being 25 years old, the board is hack-free, so I guess I can't complain.

Geebuz... how much is the Marco markup on that?
I understand the ease of ordering from a pinball supplier... but I'd almost always recommend going with a true Electronic Device supplier like Mouser or Digikey.

Zitt
I needed some other game specific items anyways. I did check both Digikey and Mouser, but due to shipping cost on a separate order all savings would have been lost.

Had a birthday bbq today for my daughter, and we all know this is when pins like to misbehave

At idle with nobody playing, I noticed a burned coil smell coming from Next Gen. Shut the game off and investigated it this evening. Center diverter under the playfield coil is burned/stuck solid. S0ooo, definitely a bad coil there, but probably bad transistor too.

While I'm not afraid to do a deep sea dive into the game manual I don't have (via IPDB), does anyone just have the point and shoot info on this? Aux board driven?

Thanks, James

Sounds like the tie back issue here: http://www.pinwiki.com/wiki/index.php?title=Star_Trek:_The_Next_Generation

Interesting, thanks. Did not know about this, I'll do some snooping around and report the findings.

I like to recommend the following hardening procedure to anyone that has experiences issues in this area.

1. Locate the +50V DC tieback wire which is a THIN violet-green wire (normally soldered to the drop down target coil)
2. Cut this wire from the drop down target.
3. Carefully extract this wire from the playfield solonoid harness back to the cable management ring below the aux driver board... NOTE: this can be a PITA to do, and you may need to cut and replace multiple wire ties along the way, but keep telling yourself that it will be worth it in the end.
4. Once removed from the harness you will have a lot of extra wire (a good thing) you need to have enough wire to reach J108-1 on the power driver board. J108-1 is an ideal location as its unused in STTNG, and pin 1 is fused by the same fuse that powers the subway coils so if you blow a fuse and loose power at this pin, you also lost power to the coils/drive transistor it protects.
5. Using your favorite type connector (I use IDC) land the wire at J108-1, be sure to leave yourself a few inches of wire for future repairs.
6. Play your machine!

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Okay, so here is the report.

I did that mod with the violet/green wire from the drop coil to the J108 pin 1 connector, which was firmly in place on that coil with the other two wires. I removed the aux board and tested all the transistors, none are out of range. I checked the pin 1 at J4 aux board, continuity is good and all appears normal there.

What can I assume happened here? What would have caused that center diverter coil to heat up and melt?

Failure of drive transistor causing the coil to lock on is the primary cause, this failure often occurs from a missing tieback voltage.
Another possible cause is a bad ribbon cable between the MPU and aux driver board, verify that this cable is connected properly on both ends.

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Okay, so.

I have a blown f103 fuse. At test for the diverters it blows this fuse. Aux board associated fuse q16 tests bad (this is the melted coil/top diverter)

I need a tip 102, and ran out. I'll have to check if I have a driver board with a ''spare'' not in use to get it up and running, otherwise I'll have to look for some at Allentown in a few days. (or just order some lol)

According to the manual, the transistor (tip 102) at q38 on the driver board is not used. Is this correct? Can anyone confirm this?

Have you checked the subway optos (left side and right side)? I had similar issues and found that those optos needed cleaning.

The best way to troubleshoot opto problems is to remove all the balls and look at your switch edge test; any opto that is not closed will require attention. This simple test will immediately identify the majority of opto issues.

I'd also check the IDC connectors at the trough in switch edge test by wiggling the harness.
On my STNG; the IDC connector's displacement grove was just plain worn and the wires were making intermittent connection leading to "multi-ball".

I've never personally had to replace the transistors (receivers)... but I imagine if you have a bad surge event; it could fry the photo transistors.

How did you test these? If you tested these by looking at them through a camera, they may be glowing, yet lack the luminescent intensity required to activate the photo-transistor.

While I feel it's not common to have so many simultaneous failures, you have to keep in mind is that these IR LED have a limited lifespan; while it's a long lifespan that's rated in thousands of hours, on a game that's over 25 years old it would not be uncommon for this time to be reached. The most cost effective way to repair these optos is to bulk buy the individual IR LEDs. You can pick up 100 IR LED's from Mouser for $25.50, which in the world of pinball is practically free. https://www.mouser.com/ProductDetail/ON-Semiconductor-Fairchild/QED123?qs=sGAEpiMZZMtdAabcSkQOlzjLIThujcXr You can also buy the exact same item for as low as $1 each from Marco if you prefer http://www.marcospecialties.com/pinball-parts/5671-12731-00

I just finished restoring mine in the fall. I replaced ALL opto pairs and have ZERO issues. Spend a few bucks, an afternoon and your STTNG will love you long time!

I sorta agree. I has so many opto issues that I replaced my brown LED emitters with new blue ones because the difference in IR output is much higher.
I do think replacing the phototransistor is a little excessive; but given how cheap they are; I can't argue to aggressively.

So my Made_Middle_Ramp switch has been cracked and intermittent (maybe 10% registered) since I got this machine.

Finally took time to put a new one in. Such a different game now. Feels like half the modes work as planned now. Alpha Quadrant was basically dead without that switch working.

Took some time to give the open area a fresh coat of one grand wax while I was in there.

I am thinking about doing a top shop of my STTNG and changing all the optos for fresh ones. This will be my 7th or so top shop.

How bad is it?