From the "Great quality control!" department, here's a Mirco reproduction ST:TNG playfield a customer recently provided to me for use in a playfield swap; notice anything odd about the right side flipper bushing hole? When my customer approached the distributor about this error, they were told by Mirco "Simple solution, use a drill bit and open the hole up to the right size." I've done numerous playfield swaps and have dealt with a fair share of mis-placed post holes, dimples, etc., but that response made me chuckle. I wonder how many folks would be comfortable drilling a 1/2" hole in a brand-new reproduction playfield through clear coat without chipping the edges or tearing out the edges of the playfield, to say nothing of getting the hole in just the right spot.

A few hours spent building a custom jig and sweating bullets, and it came out fine. I used Ron Kruzman's playfield prep kit to get some clear coat into the edge of the new hole; even though it won't see any ball traffic I didn't want to risk separation down the road.

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This playfield was supplied to me by a customer with his game, so I can't give you an exact date when it was received. But based on when I was contacted, I'd guess the customer received the playfield in early November 2020.

Was the routing of the slots for the lower inlane sensors on the back side of your playfield too shallow? The ones on this playfield are about 3/64" shallower than the factory playfield; fortunately that doesn't seem to impact the ability of the inductors to sense the ball travel, just made it a bit challenging to mount them since they stick out further below the playfield than the original mounting brackets accommodate.

Oh, and the upper mounting screw "divots" for the top rollover lane guides were mis-aligned too, but at least the narrow post base still covers the divot when the screw is in the proper position.

For $1,000 this should have been perfectly machined.

With regards to the cannon switches, it's worthwhile to replace the "mark" switches (5647-12693-58) with ones that have a roller actuator (5647-12693-06); these are more reliable than the -58 switches with the bent actuator (over time the bent part of the actuator can wear away from contact with the cam).

There was a factory retrofit kit available with the roller actuator switches (kit part number A-19153) which also included instructions on how to swap out the -58 switches, but it's pretty obvious what needs to be done: install a 1N4004 diode on the new switch in the correct orientation (banded end of diode faces switch "button", other end of diode to switch terminal on opposite end), unsolder wires to old mark switch, remove and replace mark switch, solder wires back on. Tweak the switch position as needed so the mark switch is closed when the cannon is in the home position.

Here's a picture of the left cannon, home switch at top of picture, mark switch (with roller actuator) at bottom of picture:

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Unless the ball is traveling at an exceptionally high rate of speed it's unlikely the metal ball deflector bracket is at fault; there's also not much room for adjustment there. A standard post sleeve rubber (0.453" OD) should be used on the post to the left of the bracket; I'm not sure using a 7/8" sleeve there would stick far enough into the ball path to cause bounce-outs, but it's possible. Also check the ball gate to the left of the gobble hole behind the drop target, if the gate wire is sticking up (or an incorrect one is installed) that might deflect the ball. Best bet is to pull the Borg ship assembly and take a picture or two of the area and share it here.

The Delta ramp will have to come off. Here's the order I'd tackle this:

1) Remove Borg ship plastic from Borg lock mechanism (3 screws)
2) Remove Romulan ship (1 screw)
3) Disconnect the two crossing wire ramps where they're joined above the center of the playfield (long #8 screw, elastic stop nut, 2 washers, flat metal ball guide); remember how the ball guide is oriented so you can put it back the same way
4) Remove the wire form that leads from the center exit of the Delta ramp and drops the ball onto the lower right wire form. 1 screw mounts the the right end of the wire form to the top of the metal ball guide immediately behind the upper right flipper (long #8 screw, #8 post, 2 washers). You'll probably have to rotate the wire form a bit once you've pulled it from the bracket on the Delta ramp exit so you can get it free of the lower right wire form and spiral wire form.
5) Remove 2 screws mounting Delta ramp exit to vertical riser on Borg mechanism
6) Remove 2 screws mounting Delta ramp bottom to playfield
7) Remove 2 screws mounting Delta ramp to back panel of playfield

You will be able to move the Delta ramp out of the way to access the switch on the Alpha ramp now (essentially rotate it clockwise and rest it on top of the lower left side of the Alpha ramp; there is no need to disconnect the wiring harness that leads from the Delta ramp under the playfield.

Reverse the above steps to put things back together. Leave the 3 sets of screws that mount the Delta ramp (steps 5, 6, and 7) loose until the ramp is in place, then tighten in the order 6, 5, 7.

Start at pinwiki.com and read the section on WPC game resets before you do anything; it will save you a LOT of flailing about.

The banded end of the diode should connect to the end of the switch where the actuator button* is located ("band to button"), the non-banded end should connect to the terminal at the opposite end of the switch, along with the white wire; the green wire goes in the middle.

* Or think of it as the end where the switch actuator lever is hinged.

The diode is reversed in the first picture, and in both pictures the white wire is on the wrong end of the switch; it should be on the right end as viewed in your pictures. More specifically, the banded end of the diode connects to the "C" terminal, the green wire connects to the "NO" terminal, and the non-banded end of the diode and the white wire connect to the "NC" terminal.

Yes, that's the correct wiring for any WPC microswitch using the 5647-12693 body; the "NC" terminal is used as a handy connection point for the white wire and the non-banded end of the diode. (Note that the white wire and the green wire *typically* have a colored stripe, but on some switches with an inline connector the stripe may not be present.)

Inductors (the component mounted on the wider connector - not a resistor) rarely go bad. I'd be more inclined to suspect a bad connection that is causing additional resistance in the sensor wiring that is reducing the sensitivity. The inductor (100 micro-Henries, 10%, 90mA) is actually available at Marco under part number 5551-10648-01 should you decide to replace it. Before swapping out the inductor, though, I'd check the 2-pin IDC-style connector at the end of the sensor cable to be sure the wire is making good contact with the "V" slot of the connector (or just replace it with a 2-pin crimp-on 0.100" connector).

FWIW, I have a Mirco ST:TNG playfield in the shop which has a shallower recess routed in the back of the playfield for the connector/inductor assembly (maybe an eighth of an inch shallower than the OEM playfield), and I have no issues with the proximity boards detecting the ball through the greater span of wood.

Like I suggested, take a GOOD LOOK at the 2-pin connector on the sensor cable assembly (and the other connector as well) to be sure you don't have a wire that's loose in the "V" slot of the connector pin. I'd even try CAREFULLY removing the inductor from the wider connector to see if you have tarnish or oxidation build-up on the leads of the inductor that are stuffed into the connector; removing and replacing the inductor will also tend to wipe off any light build-up.

#6-32x5/16" round washer head machine screw was there originally; they're a bit hard to find outside of a well-stocked hardware store. A #6-32x3/8" round head machine screw with a flat washer will work fine. If you're ordering stuff from Marco look for 4006-01027-06, the 3/8" long version of the original round washer head screw.

It's more likely the impact of the "head" of the plunger smacking into the coil mounting bracket has caused a groove to form in the face of the bracket, and the head is getting jammed in the bracket; I've seen that on a few ST:TNGs. Replacing the coil mounting bracket resolves the issue, but if the foam spacer is working there's no harm in going that way.

Assuming you unplugged the switch matrix wires (the white w/tracer and green w/tracer wires) at J208/J209 for your test, the odds are good you have a blown 74LS240 at U13; less likely but still possible are blown LM339s at U18 and U19 (I'd bet on U13 since all but one row is showing a short). The most likely cause is a short between the 50 volt coil supply and a switch matrix row wire (white w/tracer). I suggest you carefully check ALL under-playfield wiring to see if you can find a possible short between any white w/tracer wire and one of the heavier-gauge (18 gauge) violet/yellow, violet/green, or violet/orange wires. A wire may have come loose in transit, or perhaps a coil shifted such that one of the terminals is shorting to the metal of some mechanism.

The connectors used in these games typically have a "mating cycle" count in the range of a couple of dozen removals and insertions. Each cycle contributes to the eventual degradation of the contact in the connector (the contact begins to lose tension after a certain number of mating cycles), which can lead to intermittent issues.

02-4935-3

Check Planetary Pinball (combined with Bay Area Amusements):

03-8318-18

http://www.planetarypinball.com/mm5/merchant.mvc?Screen=PROD&Product_Code=PPS-03-8318-18&Category_Code=LG

If you ever need replacement scoops the first place to check is Mantis Amusements; Kerry makes the best replacements bar none.

https://mantispinball.com/product-category/star-trek-the-next-generation/

These *may* be sold by other dealers, but why not go directly to the source?

Go to Planetary Pinball for wire (by the 10-foot length); some of the wire I recently purchased from Marco appeared to be copper-plated something-or-other (aluminum probably) rather than pure copper.

This may not be the most useful set of pictures, best ones I have of the harness (first is prior to playfield swap, second and third are after):

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If you look a little more closely you'll see the free end of the playfield harness (with the black slit tubing) is looped back up onto the front playfield supports counter-clockwise from the bottom where it exits the playfield; I tie them up this way when replacing the playfield in the cabinet. The harness *is* routed correctly on the playfield.

Pinball Heaven in the UK sells a pair of the cannon harnesses for ~$32 USD - even with shipping to the States it's a good price in comparison to state-side dealers.

The original screws used were #6-32 x 5/16" round washer head machine screws (4006-01027-05); the 3/8" long part mentioned above (4006-01027-06) is a compatible replacement if you can't find the 5/16" variety.

F114 is the input to the unregulated +18V supply to the lamp columns; the +12VDC supply to the switch matrix for opto switches is sourced from there and feeds through F115 to the opto emitters (LEDs) in the opto switches. If you lose either of those fuses the opto switches will appear "closed" (which is why the cannons swing and the ball trough barfed out all the balls). Do you have any "mods" attached to the +12VDC supply (power driver board J117/118/119) or via alligator clips? ST:TNG sucks up much of the +12VDC supply so it's a good idea to power mods (other than perhaps a ColorDMD) from a separate power source.

It's a #10-32 x 5/8" SEMS (captive lockwasher) machine screw (part number 4010-01006-10).

The hex spacer is a 02-4935-3 2.2" spacer, the playfield post is an 02-4659-1 #10 post with female threads on top. Both available from Marco.

"Read The Fine Manual" (page 2-17 for ST:TNG): Williams recommends LocTite 245 on the coil stop, bushing, and solenoid bracket screws.

This - When the coil stop bracket gets that deformed the plunger head can stick in the groove, I've had to replace the bracket a couple of times when all else failed.

BTW, not sure why someone stuck a flat washer under the coil stop bracket, but that doesn't belong there.

Here are a couple of the assembly out of the game.

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The eddy board trim pots are Piher PT10LV10-103A2020-S (10k Ohm 20 % 0.15 W). There's a seller on eBay who has lots of 24 at $12.72 for the lot (search on the part number without the "-S").

Yes, I noticed that issue with the routing on a recent playfield swap I did for a customer. Before I dove into the swap I performed a test with the ball sensor (inductor) installed and connected to an eddy board powered via an external supply, and it seemed the sensor and board adjustments were able to compensate for the larger gap between the ball and the sensor.

During acceptance testing the eddy board showed signs of drift after the game was powered on for an extended period, so I opted to replace both the IC and the trimmer pot; the board was much more stable after that. (I had a pair of the Australian guy's self-adjusting boards on hand but didn't need to use those.)

If I do another ST:TNG playfield swap I'll adjust the depth of the routing to match the original...

A better fix is to purchase a new wiring harness for the left canon and replace the hackery that currently exists; the color-striped ribbon cable is someone's (bad) idea of how to fix broken wires in the factory canon wiring harness. The new harness will come with all the required connectors pre-installed.

As I recall F8 is connected to the spinner in the left orbit lane.

The microswitch with the roller actuator is 5647-12693-06; if you can't find one, use Stern 180-5119-02 as a substitute. (FYI, Pinball Life shows 5647-12693-06 as in stock.)

Take ALL of the balls out of your game and then compare T.1 results to page 2-42 in the manual; the switches are that are shown with a gray shading in the manual will correspond to the switches showing closed in T.1. Your right return lane switch is stuck closed...

5647-12693-06; use 180-5119-02 if you can't find the former. Pinball Life appears to stock the Williams part. The -06 switch was part of an upgrade kit released to address issues with the flat switch actuator blade wearing and breaking.

Those are commonly called "S.E.M.S." screws: screws with a captive lock washer. To check the thread size just grab a #6 screw from somewhere and see if it fits in the bracket. I believe you can find the #4-40 and #6-32 versions in the boxes of screws in the "nuts & bolts" aisle at Lowes.

No nut is used on the back side of this assembly.

I keep the heatsink (for cosmetic reasons) and insulator when I install a PSU5; there's no need for grease as the PSU5 is very efficient and runs cool. Definitely be sure to use #6 split lock washers and discrete nuts instead of the KEPS nuts (with captive toothed lock washers) as I noted over on Pinwiki to avoid potential shorts to components on the PSU5 board.

Check for a loose ribbon cable connection to the 8-driver board from the CPU board; if there's a loose connection the input will float which results in the driver transistors turning on. This can also happen if the diode tie-back connection to the 8-driver board fails. There's a mod on Pinwiki for the 8-driver board to add pull-down resistors to the inputs to prevent this failure mode (and more descriptions of tie-back diode mods): https://www.pinwiki.com/wiki/index.php/Star_Trek:_The_Next_Generation#Diode_.22Tie_Back.22_missing_causes_8-Driver_Board_transistor_to_fail

Pinball Heaven (UK) sells a good set: https://www.pinball.co.uk/game-specific-parts/star-trek-tng/cannon-looms-for-star-trek-tng-h-17067/

Light machine oil is the simplest and best lubricant for rotating shafts. At one point Williams included a "Lubrication" section in the game manual but that was omitted in games after T2.

There is a 2-pin inline connector in the wiring harness by the PC board in the middle of the lower playfield (underneath) that has the sockets for the start mission, shield, & etc. inserts; that connector has a black wire and a gray/yellow wire, which is 12V opto power, but I don't remember what is "downstream" of that connector. Take a close look and see if perhaps that is disconnected. If not, you'll have to trace back to the power driver board connector to find the break in continuity.

The rationale for making a single turn (loop) around the canon support bearing with the harness is to minimize the strain on the wires in the harness at the point where it passes beneath the playfield. I'm not sure if the guys at Pinball Heaven pioneered that technique, but here's a link to their Web page describing the method: https://www.pinball.co.uk/pinball-problems/star-trek-tng-cannons/

Your 8-driver board has jumpers at SW2, SW4, and SW6 which is correct, although from the looks of the board there may be "questionable" rework.

I've seen more problems with the ribbon cable from the CPU board to the 80-driver board being partially dislodged (or having loose header connectors) than I have with the tie-back diode connection breaking, but in any event that vulnerability should be addressed. IF you run the board without the ribbon cable connected the inputs will float and trigger the coils and flashers connected to the 8-driver board, and the result is usually at least one blown coil and/or blown flash lamps depending on the actual use of the board. (There is modification to the board described over on pinwiki.com that addresses this vulnerability.) Replacing the ribbon cable if it is at all loose is good insurance.

The lack of 12v at the cannons is not related to the 8-driver board; as I recall that power is sourced via a black & gray/yellow cable which if I recall correctly has an in-line connector under the playfield in the area of the cannons. Also check for "mods" tapping power off J116/117/118 on the power driver board which sources the 12v power.

Start by disconnecting the connector from the power junction box to the transformer (pull the line cord out of the wall first). Plug the game back in and see what happens; if the mains breaker blows either there's an issue with the wiring in the power junction box (maybe the wrong value MOV installed) OR the line filter assembly is shorted. By the way, is the correct amperage fuse installed in the power junction box? Not a cause of this problem, but it is odd the line fuse in the power junction box doesn't blow before the mains breaker.

The auto-adjusting feature of this "Tangles" eddy sensor board is a plus: https://www.tanglestech.com/TPP-1023

I've found lots of NOS "Piher" brand pots on eBay (the originals used on the eddy boards I've had to repair). You'll need to find one that matches the value of the pot originally installed on your board. Here's an example part number: Piher PT10LV10-103A2020-S; the resistance value is the number following the dash (2 digits, power of ten multiplier - 10,000 in this example).

The closest you'll get is the information in section 3 of the manual; most of the PC board diagrams have annotations for each pin of each connector showing the wire color code and destination.

A potential cause is divots in the track of the ball trough assembly causing balls to hang up on the divot; movement or shaking frequently dislodges the balls. You can dress the track with a file to remove the divots or you can buy a shim that slides into the trough and provides a new surface for the balls to travel on.

You can buy violet with green tracer wire (22-gauge) from Bay Area Amusements (aka Planetary Pinball) as part number HA-30022-75 (original part number is CW-30022-75); it's available in increments of 10 feet. While the color makes no difference electrically it's always nice to match the factory look.

Yes, that's correct, left cannon is a clockwise wrap, right cannon is a counter-clockwise wrap. Here's a link to Pinball Heaven's recommendation for routing the cannon harness: https://www.pinball.co.uk/pinball-problems/star-trek-tng-cannons/ (FWIW they make a great product.)

Switch 33 is one of the opto switches that are part of the ball popper assembly under the playfield (right side). There might be a wire broken off the opto transistor or LED boards, a bad opto or LED, or issues with the associated switch comparator board.

I've had cases where the small ribbon cable leading to the 8-driver board became dislodged (old connectors that lost tension), which will cause some of the controlled circuits (solenoids, flashers) to lock on; I've had this happen on an IJ, an ST:TNG, and a TZ.

Due to the vibration in that area it's not unusual for the solder joints around a lamp socket to crack; if all three do so the socket can fall off the board. I've occasionally found a socket (or two) in the bottom of a cabinet due to this issue. Reflowing the solder on those lamp socket pins is always a wise idea when shopping games with lamp boards.

Accidentally ripping the socket off when trying to change a bulb happens too, but since most operators can't be bothered to replace burned-out lamps that's usually more of an "happens at home" issue.

Back in the day I wrote this: http://www.dziedzic.us/wpc_speaker_replacement.html

A circle cutter (aka "fly cutter") works pretty well to make a larger hole (see http://www.dziedzic.us/wpc_speaker_wooden_display_panel.html).

I've seen replacement wood speaker panels for sale with pre-machined holes for matching 5-1/4" speakers, which are obviously an easier method if you can find them.

The holes in the screened speaker panel are of the same size, so all that's needed is to enlarge the hole in the wood panel.