I've had mine set up that way for a while. Otherwise, it's plunge/lock ball 1... Plunge/lock ball 2... Plunge/lock ball 3... Multiball! Too easy. It forces you to take the risk of sending the ball to the lower pf, shooting the u-turn (a risky shot to boot), then managing to get the ball back up top for locking. When i discovered that feature, i gladly enabled it. I'll turn it off when having parties though, most of my friends aren't pinheads and i prefer to make my games at least a little more approachable for them.

The lock memory is another feature that can be tweaked in conjunction with that to make it even harder if you really want a challenge.

Agreed. Those boards are solid once they've been gone over by a seasoned tech--many of whom can be found here at pinside. Plus, further repair services and parts should continue to be available for years to come, where aftermarket boards may not be as easy to fix or source parts for. I cringe every time i see someone with tech problems on a game with aftermarket boards. It makes troubleshooting considerably less easy than with a game possessing its original boards, in my experience. As long as the original boards are capable of being fixed, i say fix them. Chris Hibler is a repair tech that springs to mind, who's a resident expert here at pinside. Good luck whichever route you take! But don't throw the old boards out if you replace them. They still have some value even in non-working condition.

Try Mayfair Amusements for the backglass. As far as the mpu, maybe try a wtb ad here for an original or go with Rottendog if you want a new one (though i personally recommend getting an original mpu, better parts and repair availability)... Good luck!

Do the magnet buttons register in switch test? They're also on the same column as the outlanes. Check the switch matrix diagram--make sure all switches on the same columns and rows as the problem switches are working.

Looking over the switch matrix, i see both the right outlane switch and outhole switch are on the same row. I would very carefully examine *all* the switches on that row, including the *right coin switch*. Test all the switches on that row (row 4), do any other switches work?

If any of those switches has a white-yellow wire or diode that's not firmly attached, you can get weird behavior/lack of response from other switches on the same row.

Check switch gap if everything else looks ok. In order to clean the switches, take a business card or folded up piece of paper and gently squeeze it between the contacts and drag it through to wipe the dust etc on the contacts. Do not use a file, that can damage the gold plating on the contacts and make them less reliable/stop working. A file can be used on higher current switches, such as the flipper button switches and flipper end of stroke switches.

Switch matrix diagram for reference:

Screenshot_20170603-163743.png

You want to make sure your have continuity from the white-yellow wire on every switch on row 4 to the connector at the mpu. Also check the diode for every switch. To be clear, i mean check from the white-yellow wire on the outhole, right outlane, right coin switch, left ramp rollover, and the pop bumper *scoring* switch. Note the pop bumper has 2 switches--an activation switch that ball closes by rolling over the skirt/platter around the base of the pop bumper, and the scoring switch that gets activated when the pop bumper coil fires. I believe that's the switch you want to look at. You'll know which one to check because it'll have a white/yellow wire going to it. If all the wiring is definitely good and all the diodes check good (i presume you're removing one leg from the switch to test the diodes), check the switches in question for continuity. If the switches themselves have continuity when activated with your meter on the lugs as the same leaves as the contacts, it may be a board issue.

NICE!!! This was tricky because the pop bumper has 2 switches, one of which could be easy to overlook. Add to that the fact that the pop bumper worked for all intents and purposes (just didn't score)...

I had a problem on my BK a while back where the start button wasn't working. I checked so many things until i finally looked at the switch matrix and realized i had to check every other switch on the same column and row as the start switch. Sure enough it was the ball-roll tilt on the left side of the cabinet had a wire broke off (same row as start switch). That's when i finally 'got' how the switch matrix works, and perhaps more importantly: how to troubleshoot it.

Good job!

I installed mine years ago (approx 10 yrs ago), noticed similar raising of the clear above the inserts. It hasn't gotten any worse, and i don't think it's ever been enough to alter the balls path when playing. I'll take a closer look when i get home tonight. Congrats on snagging one of the repros. They came out very nice, imo.

Yup, there are plastics that can go there, but from what i understand they were printed upside down. Personally, i kinda like the steel look anyway. I have 2 sets of those plastics if you're interested in a set.

Congrats on your BK, it's a great game! (and pretty difficult)

Have you checked for correct voltages at the power supply board and CPU boards? Game won't boot with missing/incorrect voltages.

If you need help, you can always start another thread in the solid state tech forum (or PM me, I'd be happy to help watch you thru it)

Any time, man. If you need pics, advice, etc let me know. I think you've got the right idea giving the boards to someone experienced who can bulletproof them for you. These old boards are still perfectly good, they often just need some attention/refreshing (especially the 40-pin connectors, certain chip sockets, etc)... Let us know how you fare!

Good luck!

I'd clean the switches with a folded up piece of paper or business card, and also check the wiring and diodes to all the problem switches and switches adjacent to them. Give each wire and diode leg a gentle tug to make sure they're all connected firmly to the switches.

Here's a problem I'm sure others here have run into: when there's no balls sitting in the upper lock trough, at least 50% of shots to it sail right through and don't sit in the trough too be locked/scored. I've tried playing around with some brackets and stuff, but no consistent solution has come about yet. Anyone have any suggestions how to fix that?

I just measured the pitch at 6.8. My game didn't have the metal protector when i got it, and I've never been able to track one down.

Awesome, good to know! In the meantime i Frankenstein'd a couple brackets and came up with a working solution (for now at least):

IMAG4361.jpg

No reason you can't ask here! Do none of the targets register on the upper playfield or just certain ones? Did the problem just happen or has this been an issue for a while?

Yup, looks like column 5 on the switch matrix. All the upper playfield drop targets and the pop bumper are on that circuit. There will be a green/black wire going to each of those 7 switches. Check that wire (or pair of wires, as they Daisy chain from switch to switch) at each switch, give it a light tug to be sure it's firmly attached. Do the same with each diode on each of those switches as well. Sometimes they're hanging on by a thread, just enough to cause trouble. I'd start there, most of the time you'll find a wire/diode just isn't attached somewhere. Good luck! Let us know what you find.

To narrow down if it's the driver board or playfield: disconnect the switch columns and rows connectors on the driver board at connectors 2J2 and 2J3 (upper right on the driver board). You can run a jumper between any pin on the column header pins and any pin on the row header pins to test the switch circuitry on the driver board. Pin 5 of the column connector (2J2) is for column 5, so you can try running a jumper from that pin to any pin on the row connector (2J3). If the switches respond when using the jumper, the driver board should be ok (though it would still be worth re-flowing the solder on the headers for the switch matrix if you haven't already)...

Those are the correct connectors.

Are you familiar with the diagnostics for the game? You have to use the switches on the coin door (open the door, you'll see 3 push-button switches on the 'back' of the coin door)... If you have the manual, you can follow the instructions from it. If not, the manual can be downloaded for free at ipdb.org (search for Black Knight). Basically, you push the middle switch into the down position (it will stay down until pushed again, which will pop it back up), then push the 'advance' switch to the right of it. That should start the display test. Push the middle button again so it pops back up. Now, pushing the advance button again should begin the sound test. Pushing advance again starts lamp test. Pushing it again starts the solenoid test. Push the switch again for the switch test. If any switches are being activated, the number of the switch(es) will appear in the credit/ball count display (refer to switch matrix diagram in manual to decipher which switches it detects are closed).

I would start the switch test, then run the jumper between a column pin and row pin and check the display to see if any number appears. I'd probably try a working column first, and make sure it registers a switch closure (a number will appear on a display) when the jumper is on any row pin. That way you'll know you're doing the test correctly. Then try running the jumper from the pin for column five and see if it registers a switch closure when the jumper is on any of the row pins. If no numbers come up, then we know the chip Schwaggs mentioned (IC18) is the most likely culprit.

Good luck!

That's great, man! Thanks for following up. Enjoy your game!

Agreed. This is the one i use in my games: https://www.pinballlife.com/index.php?p=product&id=1245

The only ones I'm aware of are the rottendog MPUs, but they've been having trouble working properly on BK. If you still have the original mpu, it may be worth sending it out for repairs. The original boards are pretty reliable once they've been gone over by a good tech.

I checked the manual (you can download it at ipdb.org) and here's what it says:

101699770.png

You can go higher with voltage rating without any trouble. Just don't go lower!

If you disconnect the solenoid connectors to the driver board, does the fuse still blow?

Looking at the schematic, 2J11-pin 5 is the ground for the lower-left 3-bank drop target reset coil. Have you checked the coil, diode, and associated transistors for that?

I have a pair of those ratcheting crimpers, but i can't seem to figure out the trick to making them work right. I've had a 1026-CT crimper i bought from GPE years ago that I've continued using instead. Any chance someone could school me on how to use the ratcheting crimpers, or point me to an instructional site or video?

Good call, I'll give that a shot. Thanks!

Thanks for the video link! Looks like I've been using it correctly, just gotta play with the adjustment until it's working to my satisfaction. Can't wait to finally be able to use them! Would have come in handy for my most recent project where i must have done over 200 crimp terminals, lol

Have you tried running the solenoid test? Gotta make sure the outhole kicker solenoid is still capable of firing. If it works in the solenoid test, I'd verify the game is seeing all 3 balls in the trough using the switch test.

If the flashing you're talking about is coming from the general illumination, you may be able to disable the GI relay so that the lights are always just on--no flashing. Just a thought!

This is awesome! Keep us posted!

That is odd. Though i will say my BK playfield had orange inserts for the 3 Lock arrows on the upper playfield. An explanation i was given a while back is that they may have run out of green inserts for that area and opted to use whatever they had on hand instead. Not sure if that's exactly what happened but it makes sense, i suppose.

I dealt with the same problem on my BK at some point, SpaceAce. The solution was exactly what chaskett said--make sure that nail on the metal guide rail is firmly pressing the guide rail into the wood next to it. Just like he said, a good whack with a nail punch might just be the solution. Good luck!

One other thought: you said you pulled the game out of storage recently. Has it been properly leveled since? I'm wondering if maybe the playfield is flexing a little bit or something due to an unleveled stance. That's more of a shot in the dark though.

The rottendog mpu doesn't seem to get along well with Black Knight for some reason. I've read numerous threads where folks were having trouble using that mpu with bk, though the board seems to work ok for other compatible system 3-7 games.

Do you have the original mpu and driver boards? May be worth fixing them up instead...

Damn!

Is that set to 3 or 5 balls?

Have you verified that the credit button (aka start button) is working in switch test? It's switch 3 on the switch matrix chart:

_20181101_004118~2.JPG

Happens with mine too. Once in a while i can save it, but most of the time it's going sdtm.

Sounds like you may have a coil locking on when you turn the game on (due most likely to a bad transistor on the driver board). Listen carefully for the sound of a coil activating and humming when the game is turned on, and prepare to turn the game back off shortly after to hopefully spare the fuse. Zacaj is right on the money as usual, pull the connector he mentions and see if the problem persists. One other tip: knock down drop targets from each bank just in case if the coil that's locking on is one of the drop target reset coils. If any banks immediately reset when you turn the game on, you'll know it's the corresponding drop target reset coil that's locked on. That's exactly what happened to my buddy's BK, and it was a matter of replacing the driver and pre-driver transistors and the diode on the drop target reset coil to fix it. Good luck!

Also, while I'm not sure if this could possibly have any bearing on your problem Moses_1592, I'd also recommend checking the wiring to the pop bumper switch. The pop bumper switch also has an electrolytic cap and resistor. Make sure the wiring and the leads from the cap or resistor aren't touching anything they shouldn't be. If they're original parts, you may want to change them out too...

Where are you guys getting those trough protectors for the lock trough on the upper playfield?

Awesome, thanks for the link!!! It's been a while since I've shopped out my BK, this is a very good reason to finally get to it.

You may want to consider having the boards checked out before replacing them. Replacement boards have been produced, but they aren't always that easy to find. Your original boards may have years of life left in them after getting refurbished by a good tech. I had my boards repaired nearly 15 years ago and have had surprisingly few problems since. If you consider going the repair route, a couple well-known repair guys:

Chris Hibler https://pinside.com/pinball/community/pinsiders/chrishibler/contact

Clive/Coin-Op Cauldron: http://www.coinopcauldron.com/

If you're interested, Clay's Williams system 3-7 guide had written this specifically about reversing those connectors on a Black Knight pinball machine:

Oops! I Mis-Connected the Plugs and Turned the Game On!

If the plugs were cross-connected, and the game turned on, there are some likely things that could happen (this example is Black Knight; what blows exactly can be game specific, and may also depend on how long the game was powered on). First the obviously broken stuff was:
General Illumination lights.
Score displays unlit.
Flippers permanently energized and stuck on.
Drop target reset coil energized and stuck on.
Sound board wouldn't even do self test.
Blows fuses.
In this Black Knight example, here's what fried, and what survived:

Power supply board was OK.
Sound board Amp IC blown (flipper was being energized through this IC).
CPU board needed IC7 (7404) and IC5 (7402) replaced, as these were shorting +5V and ground through them (these are connected to the memory protect circuit and diagnostic switches). It also needed IC12 (7408) replaced to get the CMOS RAM working again (until this was replaced, the game always came up in test mode).
Driver board needed IC17 (7406) replaced to fix a bunch of switches that wouldn't read. Also needed IC11 (6821 PIA) replaced to fix some row inputs that were stuck "on" (surprisingly, the 4049's CMOS chips survived)

There's just one white/red wire for ground that gets screwed down with the ground strap in the backbox.

DC voltage for the magnets and flippers (what the schematic is calling (flipper B+) runs from the power supply board at connector 3J3 at pin 4 and 5. The female connector has a blue wire for pin 4 that provides 28VDC to the left flippers and magnet. Next to it at pin 5, there's a grey wire carrying the same DC voltage for the right magnet and flippers. Even if it doesn't fix the problem, i highly recommend replacing the header pins and female connector at 3J3. On both Black Knights I've worked on, replacing those header pins made a notable gain to flipper strength. In one case the flippers weren't working at all and it was just worn out header pins on that connector. I remember the pins had a sort of dull appearance compared to others. Seeing how much more work the flippers perform than the other coils, i suppose it shouldn't have come as a surprise.

Thinking in a different direction, have you verified the magnet button works in switch test?

Yup, normal behavior. Nothing to worry about!

Wrong club, lol! Nice looking High Speed though!

Each time you complete a bank of targets, you get an arrow lit next to the bank. To get EB, you have to complete all three arrows for both of the top 2 banks (6 arrows total), or the bottom 2 banks, or all 4 banks (depending on eb difficulty setting).

Doh! Read that too fast. Special is obtained only during the "bonus ball" in multiplayer (winner of the game gets an extra 30 seconds of unlimited multiball)... During the bonus ball you have to knock down all 4 banks of targets once--that lights the u-turn Special. Very hard to light it, and even for the amount of times i may have lit it, I've only ever *collected* Special maybe 2-3 times in 15+ years on my game. I don't play nearly as much multiplayer as i used to when i first got the game though.

Inlanes and outlanes advance 2 bonus. A successful magna-save advances 5 bonus. The rollover at the top left of the upper playfield advances 1 bonus. Knocking down a bank of targets advances 3 bonus. I think that covers all of them...

The 2's will scroll on a couple displays when 2-ball multiball is going on. Same with 3's during 3 ball multiball. It sounds like this has something to do with the lock trough switches on the upper playfield and/or the main ball trough switches at the bottom of the main playfield. If they aren't adjusted properly the game might be getting confused as to how many balls are locked/in play and cause weird behaviour like that. That's where I'd start--fairly common issue on this game.

Coil stops are replaceable on BK, i did so when i bought mine years ago. Of course, it's more than just the coil stop--it's the whole flipper bracket with the coil stop built into it. Pinball life has them for $14 each.

Left side: https://www.pinballlife.com/willilams-flipper-mounting-bracket-and-coil-stop-assembly-for-system-6-7-machines-left-side.html

Right side: https://www.pinballlife.com/willilams-flipper-mounting-bracket-and-coil-stop-assembly-for-system-6-7-machines-right-side.html

I think there's another company running new BK playfields soon, Mirco possibly? Hardtop may also eventually become an option as well.

Chris Hibler here at Pinside has a good reputation here as a board repair tech.

The Coin-Op Cauldron does good work, as well.

I definitely recommend having your original boards repaired instead of buying new 3rd party replacements. Some are good, but original boards are usually quite reliable once they've been gone through by a good tech.

Williams System 7 games have numerous quirks that typically need to be worked out to be reliable, including new 40-pin connectors between mpu and driver board, chip sockets often go bad on the mpu, 8a slow-blow fuses need to be added to each of the 2 backbox-mounted bridge rectifiers, new caps and connectors on power supply, etc etc etc. Check out Vid's guide to bulletproofing Williams System 3-7 games, he covers everything in great detail: https://pinside.com/pinball/forum/topic/vids-guide-to-bulletproofing-williams-system-6

Congrats on your BK, it was my first pin and will never leave my collection. Not only for nostalgic reasons, but because it is just an awesome game through and through. The art, the gameplay, the sound of the lit spinner blasting off from a good shot, the magnets, the Knight, and of course the hordes of drop targets! You'll be up and running in no time with the help of the folks here. Good luck!

Speaking of the coin door, does anyone know what goes in the center slot on this one? Is there a particular insert or decal or something for that space? There's a spot for a gi lamp behind it, so i figured it might have had some sort of insert like the "Quarters" signs that go in the adjacent ones.

IMG_20190730_160706.jpg

Good to know! Anyone know where i might find one of the Williams logo plates?

In my case, it looks like the provisions are there for a 3rd slot, it just wasn't used (and mech removed seeing how the switch wires are taped off)

IMG_20190730_174802.jpg

Wow, thanks for the detailed post! That looks great!

Agreed, i had 2 Black Knight's that both benefited greatly by doing new male and female connections for ground at the driver board and for flipper power at the power supply board.

In one case i replaced nearly everything in the chain. (cab switches, eos, coils, driver board connectors) and didn't get anywhere until the new connectors for the flippers power (28v i think?) were installed on the power supply board. That got the flippers not only working, but working nice and strong to boot.

After that i went to my own BK where i always felt the flippers needed a bit more power. I had already rebuilt everything except for the that same connector on the power supply board. Since rebuilding that connector, I've had shots rocket up the left spinner ramp with flippers that were last rebuilt nearly a decade ago.

Worth a look!

Offset!

Edit: transformer in backbox, system 6 power supply board as well

IMG_20200226_162148.jpg

Put the game in switch test (reset drop targets and remove the balls first), test each drop target manually and see which number gets displayed for each one. The manual shows the number for each switch on the switch matrix diagram.

Do you have a part number for that plunger? I was looking in the Addams
Family operators guide and there's a few different kicker/kickout assemblies on it. Is it the one for the electric chair?

Edit: would a higher resistance coil be an alternative solution?

Thanks!!

Chris Hibler, a member of this site, is a good repair guy. Here's his website: http://chrishiblerpinball.com/

The Coin Op Cauldron has done repairs for several of my boards, great company as well: http://coinopcauldron.com/

Can't go wrong with either of them.

Welcome to pinside, by the way! You found a wealth of good info and people here. A word of warning though: pinball machines can start multiplying before you know it. You may find yourself measuring up space for the next one...and the next one... then one day half your dining room is pinball machines, and you move the table over to fit *one more* and then suddenly back porch starts slowly filling with games...

Be sure to follow up here with any questions you have along the way--this site has some of the most helpful folks I've ever met. Don't be afraid to ask--even if it seems like a really basic question we all had to start somewhere.

We want to see your Black Knight ride again!

Good luck!

Setting #38 is locked ball lamps:
Memory: 00
No memory: 01

Think that's the one you want to toggle.

In particular it's the 2 large wiring connectors between the head and cabinet that are the same size and keyed-alike. They're 36-pin connectors or something, you'll know when you find them. Don't mix those 2 up!

Pushing the button on the right should take you into either audit mode or diagnostics/test mode depending whether the middle button is up or down (first click pushes it down, 2nd pops it back up). It doesn't appear to be responding to any button on the coin door.

I'd check the wiring and diode each switch on column 1 of the switch matrix. I usually give the a light tug at each wire and diode leg to make sure they're all connected firmly. Also make sure none of those switches are stuck closed, and that the solder lugs aren't touching anything adjacent or mashed together.

IMG_20201018_190142(1).jpg

Post pics of the wiring to the coils and eos for the problem flippers. My guess is a wiring issue.

Different magnet relays too...at least on my buddy's LE they're different from the relays on my non-LE. I can't explain why but the magnets on his game are notably stronger on his game than mine. I'm still trying to figure out why

They're definitely stronger. I'll have to take videos to compare. We both have our games set to the factory settings for length of time the magnets activate. On my game, you might lose the ball 40-50% of the time from a magna save, especially if the ball is moving fast when the magnet catches it. On his, it successfully saves the ball like 95%+.

I've tried new connectors and headers from the magnets to the power supply board and I've got a solid ground connection on the end of the white/red ground wire. Nothing I've tried has improved or weakened their performance. Next up, I'm trying new magnet cores and relays. I don't expect to see any drastic change, but i want to try everything i can. I guess I'll try new magnets eventually, but i could swear i tried some years ago. It's just weird, i always thought the magnets' behavior on my game was normal until i saw how strong they are on his LE.

Yeah, tried filing the relays contacts too.

I have wondered about the possibility of doing something like you suggested, but i figured I'd cover all my bases and make sure there's nothing I'm overlooking. I'll have to get a closer look at the relays and coils and compare resistances on the magnet coils next time i get a chance to get a look at the LE again.

Have you tried turning the game on/off/on again? When the batteries get replaced or ever get removed from the MPU, the game will go into "audit mode" which displays the stuff you're seeing. By doing the aforementioned suggestion, that might get you past audit mode and into attract mode. (Though if the batteries and RAM are good, you shouldn't have to do it again until you change the batteries)

Edit: you may have to do that on/off/on with the coin door open

Make sure to check the ball lock switches on the upper playfield as well. A problem with those can also cause the game not to start or cause ball detection issues.

Make sure the outhole switch is adjusted properly too. The ball may not be pushing it completely closed sometimes.

Also check the wiring and diode to the switch and make sure everything's firmly connected. A light tug on the wires and diode legs can help reveal a weak connection.

Have the general illumination connectors been re-pinned? Did you pull the fuses and test them with a meter?

Out of curiosity, do you have the original power supply board installed, or an aftermarket?

In that case, you may want to try replacing the header pins for the solenoid/flipper power connector on the power supply (3J3), in addition to it's female connector. (Though it looks like you might have already covered that)

I've seen a notable difference on my BK flipper power since replacing that connector. The pins for the flipper power (pins 4+5) were a bit dull compared to the other pins. You may also want to re-pin the flipper ground connector on the driver board (male and female sides) at 2J12. (Not sure if that one's been replaced on your game yet)

May also want to try new cabinet switches if all else checks out.

My guess would be that the EOS switch didn't open, keeping the low-resistance winding of the coil activated for much longer than it should. That would def burn a coil.

Had you done any work on the flippers recently? I've gotten in the habit after doing a flipper rebuild, play a few games and then re-check the EOS gap and also make sure it's tightly mounted to the bracket etc.

Unfortunately this is how we learn sometimes. I went through a very similar experience myself years ago

A new coil and a properly adjusted Eos and you'll hopefully be good to go. Have you already rebuilt the flippers? If not, this would probably be the right time to consider doing them (even just the lower flippers)...

Did you find adjusting the Eos made a notable increase in flipper power before the coil fried?

Yeah--that made me do a double-take too!

Looks like it's a special vinyl for Black Knight: sword of rage--

https://littleshopofgames.com/shop/shirts-hats/black-knight-sword-of-rage-fire-edition-lp-vinyl-record-album-scott-ian-anthrax-883-5002-00/

I think i may have found a clue as to why my buddy's BK LE has noticeably stronger magnets than my non-LE. Not sure what exactly is going on here, but each magnet relay was hooked up to one of these little junction boards with a ceramic resistor. I definitely don't recall seeing these on my game:

PXL_20211120_000314221.MP.jpg

Has anyone seen these on their BK? Anyone know what function they serve?

The GI should already have a fuse, it's probably on the power supply board (the board above the rectifiers). Otherwise there's usually a fuse card in the backbox close to the area the rectifiers are located (though I don't see it there in yours, so I'm assuming it's on the board)...

You're doing the right thing installing those 8A rectifier fuses. You may even want to swap out the rectifiers while you're in there--they're like $5/pop or something. Not necessary, of course--but might save you some trouble down the road.

One other thing--check all the other fuses in the game and verify they are correct rating and type (fast blow/agc vs slow blow/mdl)...it's rare for me to find a game with all the *correct* fuses installed

Good luck with your Knight!

I like your plan of splitting up the GI strings and fusing them individually. I've read about doing that at some point, but I don't remember where I had found that info. Hopefully someone here can chime in with the fuse values.

As far as the bridge rectifiers, I usually use these from Great Plains Electronics--35 amp/400 volt

https://www.greatplainselectronics.com/proddetail.asp?prod=GBPC3504L

Another thing--does the GI circuit a 20 amp AGC/fast or an MDL/slow blow fuse? I've been under the impression that it uses an AGC/fast blow.

Congrats, and welcome to the hobby! Excellent choice on a first game, Black Knight was my first pin as well!

I would suggest getting more familiar with the diagnostics in order to help us troubleshoot. Luckily, one of our members here on pinside made a video demonstrating how to navigate and interpret the diagnostics on a Black Knight, of all games!

For further research, I would recommend checking out pinwiki.com. (for sake of research etc, Black Knight is a Williams System 7 game) There's also tons of useful tech threads here on the forum, and lots of videos on YouTube and elsewhere documenting repairs etc.

There's a lot to digest, so take your time and ask questions when needed!

For now I'd suggest learning how to use the diagnostics to get into the switch test and then tell us which numbers the switch test is displaying. That will hopefully point us closer to the culprit.

I'd also get familiar with removing the playfield glass and tilting back the playfield to access the under side etc. I'm sure there's videos demonstrating that as well.

Again--ask questions if you aren't sure, and can't find the answer here. These are old games and many of their problems have been documented here repeatedly over the years. It's likely most problems you'll encounter have been discussed here at one time or another! We'll get your game fixed up given enough time and persistence

You aren't booting into audit mode by any chance? Do the displays show anything when you turn the game on?

If the problem all seems to point to 3J3, I'd repin and re-flow the connector. Cleaning is never a permanent solution, at least in my experience. You've come so far--you just need to get it past the finish line! Hopefully you'll finally be 100% with the connector replaced/reflowed.

If you have new header pins, it may be worth replacing them instead of just re-flowing the original pins. I noticed the pins on the 3J3 connector were a bit tarnished/dulI on my BK and wound up replacing the header pins along with the female connector. I found a noticeable improvement in the flipper strength afterwards. It's probably worth doing the work there regardless whether it fixes the problem or not.

If that still doesn't solve it, I'd trace that white-red wire back to the playfield--there may be a connector somewhere down the line that needs to be replaced (or bypassed for now). Looking at the schematic you posted, it's 8J7/8P7--perhaps it's a 1-pin connector...?

Agreed--if the flippers have been working fine the whole time, I'd imagine it's a ground issue for the magnets. You've got to be close to the solution...

Since you've tried nearly everything at this point, it really wouldn't hurt to try replacing the female connector at 3J3. I remember going through hell trying to get a buddy's BK flippers working and after trying nearly everything, it was replacing both sides of 3J3 that finally fixed the problem. I was reading correct voltage at the coils before and after the fix--can't always trust the meter on some of these repairs...doesn't always tell the whole story.

Here's a couple diagrams with part numbers from a couple of earlier parts manuals... Hopefully the part numbers are relevant: PXL_20221221_021748988.jpg
PXL_20221221_021804480.jpg

I would imagine you can re-use the housings, you'll need pin extractors to get the old ones out though.

You're welcome!

I just happened to come across those diagrams the other day while searching for something else in those manuals. I remember thinking I might need that info again sometime, didn't think it would be this soon though lol!

In case it helps, these were the guides I took those pics from:

PXL_20221221_205855547.jpg

Looking great!

How's it playing?

Make sure there's continuity between the green-brown wire daisy-chained at all the switches on the same vertical column as the start button (called the Credit Button in the manual) and up to the connector in the backbox at 2J2 pin 9 on the driver board.

Screenshot_20230416-215248~3.png

Make sure the diodes are attached firmly at those switches as well. One broken wire or diode at a switch could cut one or more other switches out of the circuit...

Lol, that was *exactly* what I found on my BK years ago when I was having a problem with the credit button. Discovering that solution really solidified my understanding of how the switch matrix works and the way the wiring daisy-chains from one switch to the next.

Nice work!

I just checked a driver board I have on my bench. There should be continuity between the 2 purple arrows, and continuity between the 2 yellow. No continuity between yellow and purple.

Just to be 100% sure: did you pull fuse F2 out of its holder and check it for continuity? Are you getting voltage at the coils under the pf?

Have you done any work on these boards yet? I remember getting random sounds during attract mode when I had a problem with one of the ROM sockets on the MPU. Have you tried re-seating any of those ROMs?

Another suggestion would be to replace the header pins and female connector at the MPU (1J8) going to the sound board (10J3).

I would replace it with a new leaf switch. That one's just worn out, more than likely. It's also possible someone might have tried filing the switch at some point, and that will damage the contacts--worsening the problem.

That said, I'm interested if there's a microswitch that would be a proper fit...

Mikespinball are you using original boards or aftermarket? I'm thinking possibly a lockup on the mpu/driver could have resulted in a locked on coil (eventually blowing the 8a fuse -- good thing you added one!)... are any transistors fried on the driver board? Any toasted coils?

Have you verified the switch has continuity when closed using a multimeter? Are you sure the diode and wiring is installed correctly?

If all checks good there, you might have a wire or diode leg broken off one of the other switches in the same switch matrix vertical column or horizontal row. Check the switch matrix chart and see if the other switches on the same column or row are also registering, you'll often find more than one switch is not working when there's a problem with the switch matrix. If that's the case, check the wiring+diode at each switch on the same row or column. A light tug may reveal a loose connection...

Nice! Love an easy fix

It's a shame, i was really excited when Mirco first hit the scene. They really went out of their way to crater their reputation over the years though. I have been waiting on a repro for Nine Ball and even though they finally made one, I'll wait for someone else to. They aren't worth it!

Check this thread, we just recently helped another pinsider get their BK flippers up to snuff. Just about everything to check is there.

https://pinside.com/pinball/forum/topic/bk-flippers-still-weak#post-8035445

Follow up with any questions!