Hi folks! I just joined the club a few weeks ago and am thrilled about it!
Scored a player's machine in nice all-original condition. Runs 97% perfect. Early production unit with xformer in backbox.

I first fell in love with BK in 1980/1981. I was 13 years old, and this amazing new machine appeared at Family Fun Arcade in Granada Hills, CA.
Over the 40 years since, I've only seen this title a handful of times. Like visiting an old friend, every time. It made a lasting impression.
So very glad to own one now. I appreciate it even more now than I did when I was a young teen with $3.00 in quarters in my pocket.

I'm enjoying playing AND restoring, but I could use a little guidance from this august fellowship:

1. Playfield conditioner. Is this a thing? A good thing? My PF is clean and in pretty good shape, though the surface looks DRY. Should I be treating the PF surface with something, or leave it dry? To be clear, the PF is all original, no overlays.

2. Connector KIT - I want to completely redo all my Molex/nylon connectors. Is there a PB parts vendor who would carry all the odd connector shells, pins, and even crimping tools for a System 7 boardset & harness? I'm an old electronics guy, so I'm comfy with soldering and such.

Any advice you can offer is much appreciated! Thank you, one and all!

-Andy

These are all excellent bits of advice!
Many thanks to you both, koji and BobLangelius !

I welcome any and all opinions about playfields and anything else about BK maintenance and repair.
After all, this BK is my first pin owned, so I'm still a noob about the maintenance aspects.
That said, I'm having a grand old time restoring this pin, and playing frequently during the process.

Naphtha and wax/buff have already noticeably improved the overall action.
New inlane guides already on order. I have serious hop on the right side.

What about viable flipper upgrades to address the marginal strength?

Thanks koji
Finely adjusting that EOS switch made much more of a difference than I would have expected! That flipper's strength is totally acceptable now.

At this point, my BK is 98% 'perfect', but this last problem has me stumped, and it just started happening a couple of days ago:
Out of nowhere, it suddenly has a very hard time kicking a new ball into the shooter lane.
It kicks a ball out (quite powerfully), the ball bounces off the metal plate on the facing wall and falls neatly back into the trough. Kicker tries again. Repeat ad nauseam.
This repeats until I jostle the machine just right, or sometimes it will 'accidentally' fall out of the pattern and into correct position for launch.

I manually actuated the kicker arm and was surprised to find it seized up. It moves, but not well.
I figured that couldn't be right, so I oiled the hinge point. Now it rotates freely, but I was astonished to find that this made no noticeable difference in the problem.
I tried restricting the in-game actuation with my hand, and found that a ball would serve up seemingly normally if I keep a restricting finger on the kicker arm.
Is the kickout suddenly too strong for the job? Is the coil cooked from the seizure and getting ready to croak?
WTH? I played HUNdreds of games over the past several weeks, and this never happened even once, and now it happens almost every time.

Does anyone here have any clue what the heck my problem is?

This fixed the issue handily, slochar
Many thanks!

I have a question about Driver board jumpers W9 through W16 ("Switch Columns Drive")

I've read several times that these driver boards were also used in earlier machines, but with resistors in these positions,
and when used in a BK, these resistors should be jumpered out.

Well, my BK has the resistors. And the game seems to perform just fine (other than some rollover leaf switches not triggering consistently when the ball is moving really fast, even though they detect 100% in diagnostics)

Should I jumper these resistors out?
If so, fine, but WHY? What does adding the jumpers actually DO to the circuit?
Or, to ask another way: What is my BK doing sub-optimally because it has these resistors?

And the obvious follow-up question: Are these resistors linked to my horseshoe switch detection flaw? Does anyone have advice about how to improve responsiveness of rollover switches when the ball is really flying around?

Many thanks to all who offer advice.

Thank you slochar
I went ahead and replaced the 330-ohm resistors with jumpers. It was the right thing to do.

I also did manipulate the wireform on the horseshoe switch (and a few others as well). Easy-peasy.
Strangely, it had no effect I can see during gameplay. It still registers inconsistently. Perfect and sensitive in diagnostics, random during actual gameplay.
I'm gonna assume it's down to the mis-manufactured leaf switch, as it is otherwise properly gapped and straight-leafed.

But a good many of the leaf switches in this unit are the notorious backward leaf contact-on-rivet mess. I'm feeling like I should just replace them ALL. They're 40 years old, they should probably be retired and replaced anyway.

Thanks again.

Has anyone else seen this confusing game behavior?
It happens randomly, maybe once every 100 games:

Ball in play, as normal. Scored a few thousand points, got a couple of targets down, timers going...
Ball drains for normal legit reasons, but is NOT handled as an End Of Ball Event.
Instead, the ball is served back up to the shooter lane, without acknowledgement or sound effect. Ball-in-play number does NOT change.
Those couple of targets are still down and the timers are still running, as if the ball had never drained at all.
Game never leaves ordinary ball-in-play mode. Timers expire, targets reset, game waits for me to re-launch the ball and resume play, as if everything was otherwise normal.
No specials or bonuses lit at any point.

I lost that ball fair and square, but the Black Knight is handing my dropped sword back to me?! For nothing?
What the heck is happening here? Does this "chivalry bug" behavior sound familiar to anyone?

Perspective: I've had my BK for only about 5 weeks now, and it has happened 5 or 6 times in hundreds of games.

slochar & frenchmarky
Yes, that must be it. Me and my GF both seem to recall that it always happens when we 'turbo-drain' the ball, particularly from the left part of the PF. (the angle most likely to fly past the drain switch)

Actually, that's all fine with me; I just wanted to make sure I didn't have another failing diode or board problem that could be corrected.

I think at this point, my BK is playing about 99.8% perfect, and I'm very happy with it.
Thanks, folks!

Is there a Master Parts List?

I want to replace all the unreliable leaf switches and some of the Molex playfield connectors (8P1-8P8), but I can't find part numbers.
They are not called out in the manual or schematics, that I could find.

Would any BK owners here have the part numbers for these?
I have spent way too much time in Google Hell and have found almost nothing. Why is this info so hard to find?
Most PB specialists will carry the 12-position power plug and a Generic Williams leaf switch or two that MIGHT fit, or maybe not?

Can anyone enlighten me?
Many thanks!

This was exactly the Rosetta Stone I needed!

Many thanks, slochar !

Hilarious.

That catalog is weirdly missing the entire section containing connectors (and electronics).
Another website had a downloadable PDF of same, but also missing the electronics/connectors section.
I'm guessing that section was big and complex enough to be broken out in a separate book...which is MIA.

Drat, foiled again!

Does everyone just repin their existing molex connectors?

Looks applicable!
Now THAT's the Rosetta Stone I really needed!

Thank you so much, frunch !

BLUE Drop Targets?

I know somewhere in this 56-page thread, I saw pictures of someone's BK that has blue drop targets on the left side of the PF.
Are those commercially available somewhere, or was that a homebrew 3D-printing project?
I'd love a set of those blue ones for my table.

Michel_K17 -- This is great! Packed with practical information! Thank you so much for sharing this!

As for the leaf switches, I finally got myself a copy of the Williams 1980 parts catalog, which does have the leaf switches in it--just gotta find modern sources for some of them. My concern is that some models have become 'unobtainium' over the years.

In any case, thank you very much for this trove of info!
-Andy

SteelTigers , I also have an early production unit, and I reused every single one of those standoffs when I replaced all my plastics a few months ago. I had assumed that these parts are only available from 'parted out' machines, which I don't have access to.

I used a philips screwdriver to (slowly and gently but also very firmly) push the rolled edge back through the hole, then used needle-nose pliers to manually unroll the edge just enough to push it into the new hole. Then I used the same screwdriver, stuck it in the tip that I just unrolled, and pushed down while rotating, to 're-roll' it.

It may be a little crude, but it is also very effective. Once mounted, nobody could ever tell the difference. Works fine, looks fine, job done.

Good luck!

For the riveted pieces, I drilled out the rivets and reused the brackets. Instead of a new rivet, I used a #6 nylon screw and nut to reconnect, then painted the nylon screw head red (with a Sharpie) to match the plastic. Invisible unless you know to look directly at it.

You should be. Congratulations!

I got mine just a few months ago, and I love and appreciate it more now than I did as a kid in 1980.

Unsolicited (but sincere) recommendation for you or your restoration technician, while you're waiting for the Knight to put his arse-kicking boots back on:

Jack up your playfield incline to 5.2 degrees.
(inclinometer on PF surface, not on the glass)

Those 2 bulbs are 'user mods' (albeit not uncommon--I added the same to my own BK). A stock BK has NO bulb sockets in those positions. If you look at any 100% stock BK, the upper right quadrant of the table is pretty DARK.

It may look like that lower hole is meant to house a bulb, and maybe was intended in the original design, but in actual production, were not socketed or wired. Likely as a cost cutting measure.

All that said, I think those bulbs SHOULD be there.
My 50+ year old eyes hate a pin with dark areas.

Okay folks, I have a weird one for ya:

My BK is tuned to perfection and plays great.
However, recently a new problem appeared:

After a few games, the lower right flipper will occasionally stick in the up position, even if the flipper button is totally open. Like the hold coil is (partially) energized when it shouldn't be. But I don't think it is really energized. It makes no coil hum, and sometimes it will just fall back down all by itself or if the ball hits it

If its up, and I tap the flipper button a few times, it will release and drop back down and continue working normally...until the next time it sticks up.

The flipper shaft has zero friction to the touch, and is properly spaced from the PF (about a credit card's thickness).

Seems like conditional mechanical binding, but when I touch the flipper with my hand, it feels absolutely FINE, smooth, clean.

Anyone have a clue what I might be missing here?
The machine behaves perfectly in every other respect, and only this one flipper is affected.

I am mystified.

Hmm, this does sound similar to other threads that mention stuck flippers that otherwise perform nicely.
Evidently, the coil stops are common culprits for getting magnetized(?)
Weirdly, these are all new (less than a year old) full flipper assemblies from PBL, and they work great otherwise.

What causes this, and why isn't it happening all the time to all machines? I've never even heard of it before today.

I own a bulk tape eraser AND a tape head degausser wand. Do you suppose either of these tools would be effective in disrupting/removing this magnetism?

Thanks.

Are you testing it from the game's diagnostic mode, or just checking during live gameplay?

And is that the ONLY switch that doesn't register?

Love a happy ending.