...than fake ones.

Say they cost Stern $20. Times that by thousands of pinball machines over the past couple years and you have some money saved up. Same with aprons and etc. Every dollar saved times x amount of machines is profit

sad but true

Yeah, that is my webpage. Funny thing is that I stopped putting them in a while back because I usually played Tournament games on my Stern games. In that case you never got a knock during the game and there is no match sequence! I did put one into LoTR and I am probably going to put one into ACDC soon. Once again I am not sure that ACDC will knock if you have replay set to extra ball (as I do). In that case a second replay level close to the first one set to award replay instead of extra ball will produce the knock...

One of the things that I have found is that the new Stern cabinets are sturdier than the older cabinets and are therefore more sound dead. If you do install a knocker, I suggest upgrading to a 23-700 coil for a little extra pop (I once put in a 22-600 coil and really made it loud!!) . Also, finding a place in the head to install it makes a big difference. Another alternative is to install it in cabinet so it hits the middle of the side (away from corners of the cabinet where there can be a little more resonation) like in the pictures from TAF above - only without the rubber pad. The rubber pad is what gives the knocker the "bear kick" sound in TAF.

Heh! Small world.

PT, or anyone, I bought the knocker and step up board before I realized there was a complete kit so I am going to have to build a harness. No problem but is there a place on the board to tap into the 50v without needing to build a Y adapter? I would rather not solder into a coil on the playfield. Besides, I can't seem to find those 3 pin connectors with the weird shaped plugs that Stern uses.
Also, from the pics it looks like the kit is tapped into the 50vAC. I thought coils were 50vDC. Or am I mistaken?

I also bought the parts rather than a kit, and I noticed the same thing. The kit does use 48V AC, and is only fused by the main fuse before the transformer. I ended up making they equivalent of a Y connector to plug into J10 on the power driver board. That way, I can use fused 50V DC, like all the other coils do. I also installed it in the backbox and ran the Q24 signal up into the backbox rather than running power down to the cabinet. I can post pictures of what I did if it would be helpful.

I may steal this for my avatar pic

Thanks herg. Yes Please.

Here's a few pics of my install. I just realized that parts I already had for LED OCD may be a bit more difficult for someone else to find.

The Z-Connector can be bought at Great Plains Electronics.
The IDC connector that Pinball life sells is for 22 AWG, and you definitely should use 18 AWG for tapping into J10. I got mine from Heilind.com, but they have a $10 minimum order. The part number is CT156F18-10.

IMG_5301.JPG IMG_5302.JPG IMG_5304.JPG

Oh, and there's certainly not a problem with it being too quiet mounted here. It's a SOLID knock!

pardon my ignorance but what do knockers do? Ive heard the screach but never knew what it was

They signal that you have just won a free game (replay). It's meant to get the attention of not only you but also others who might be in a public location, to give you some attention for crushing the game.

Thanks for the pics. I am assuming you tied into j7p10 for the Q24?

No, I actually used the three pin, 0.062" molex connector that is near the tilt bob like it is described in PT's instructions and ran the wire all the way back up to the backbox. You certainly could connect at J7, though. I like to avoid the stacked up connectors when possible, but I saw no other good way to get 50V DC. The extra wire is also cheaper than the connectors would have been.

OK I misread it. Thanks. I will just go plug down into the cabinet connector.

I got a chance to see inside one of the kits that PBL is selling, and there is a custom PCB with a rectifier and fuse. This means they are converting from AC to DC inside the black box, and there is no issue with it not being fused as I originally thought.

I just wanted to make it clear that their design looks fine, and it should work pretty much the same as if it were connected to the 50V DC on the power driver board.

If you doing it yourself, do not connect 48V AC directly to the step-up PCB or coil.

Herg- I got all my parts ready to put this together and notice that the 8th pin on J10 also is 50+ and is unused. It looks like you used pin 9 -- why not just use 8 for positive and 5 (like you did) for ground and be done? That way you could just push wires into the existing connector.

I realize making the Adapter makes it more plug and play - but even if I wanted to remove it I could still just pull the wire out of the connector. Am I missing something?

When I was building these, I was making them for multiple machines. Some of those already had a wire at pin 8. Pin 8 is designated for magnets or other special cases and has a separate fuse from pins 9 and 10, which is designated for coils. Also, I was helping a friend install these in their machines, so I wanted as much done ahead of time as possible.

If you have a game that does not have a wire pressed into pin 8, you could use it. Be aware that the fuse will likely be a 4A SB, so it is bigger than the 3A SB that is used for ALL of the other coils in the game. You might want to consider reducing the value of the fuse as well.

Thanks! I bought all the connectors to do the stacked but didn't know why there was available 50v at p8 and just ended up adding the wire but will now reconsider due the fusing. Since I had to buy so many minimum quantities I had planned on building a few at once as well just to make use of all these parts! Now I just have to get the little guy working. If I short the transistor on the step up board it knocks, but I can't get it to knock in coil test or knocker test mode... will re-check the signal wire today and the software settings.

I think I had read somewhere that it didn't work in the test modes. I know that it does work at least on some of my games, so it might be game dependent. Test it in game if possible to eliminate that possibility. If I remember correctly, the only settings that need to be made are to select the Q24 option and to turn off the fake knocker volume. Good luck.

So you mean I have to spend the morning playing Tron until I qualify for a high score? Tough morning at work for me today.

After I double check settings I'll give that a shot before messing around with other stuff.

Thanks-

Just set your replay score low... unless you just want to have an excuse to play a bunch of games.

Well, that's what I did - and SUCCESS!! I spent considerable time last night trying to figure out why the heck this thing didn't work. I mounted in a similar location as you did, but used a stacked connector for Q24 since I didn't have the appropriate molex for the plug in the cabinet and as described above used the p8 for the 50v. So - note to future knocker installers, coil test and knocker test may not work, so you have to test in game play.

I now have no fake knockers in my house and am pleased.

Very new to pinball mods (this will be my first one) Where do I buy the molex conectors and what ones do I need for this project? Thanks for saving my ears from the stern banshee.

I installed everything according to the instructions and there in no knock. I hooked up to pin #8 on my POTC. Can anyone help me here?

We need a little more info. Post some pictures of your installation, and maybe something will jump out at us. Set Q24 for knocker? Probe for power at the coil?

Damn I knew there was a step I didn't follow. I did not set Q24 to knocker. I will try that tonight. Thanks Herg

Ok I don't know how to change q24 to knocker where is that option?

Found it KNOCK!!! Thanks everyone

Q24 is option 55 in the standard adjustments.

So, I'm installing another one of these, and the Stern step-up board is a new revision. Even the pinout of the connector is different. Sure, we're using it for something not really Stern approved, but how does this work for games that actually use the 520-5254-00 for a "Stern approved" design?

rps20140721_223241.jpg

It does seem strange that they put that weird sound in there instead of just making it sound like a mechanical knocker.

For comparison sake, here is a picture of the old design:

image3041.jpg

...and here is a link to a thread talking about it being used in Metallica to drive Sparky.
https://pinside.com/pinball/forum/topic/noob-question-metallica-pro-sparky-doesnt-shake-at-start-of-multiball#post-1093154

130360.jpg

You can see in this picture that pin 2 is not connected to anything, and I'm guessing that it is probably even keyed so that connector would not plug onto the new step-up board.

In my case, trying to use it to drive a knocker coil, it doesn't fire when it's supposed to, and I'm guessing that connecting 20VDC to pin 2 would make it work.

I still want to know what the repair procedure would be if, for example, Sparky stopped working and I needed replace his board.

I'm interested to see how this new board unfolds as I plan on building another soon. Thanks for posting up what you are finding.

BTW, one of the old step-up boards makes the new knocker installation work fine. It just doesn't work with the new board.

Could the board be mislabeled and the 50 V is supposed to go to pin 2 on the new board? Is Sparky 20V or 50V?

Sparky is a 50V coil, but it is driven by one of the 20V drivers on the PDB, which is why the step-up is needed.

Best I can tell, here are the schematics of the two.

1309_001.jpg

Assuming I didn't make a mistake drawing the schematic, there's going to have to be a connection to the 20V pin for the new circuit to work. This would be true when using it for a knocker or if you were replacing a Sparky board.

I just gave it a try with 20V connected, and it works as expected. It still doesn't solve the mystery of how repairs would be handled, but it gets my knocker working with a minimum of extra effort.

Any pics of the new install? I just ordered a Metallica as well as the knocker parts from pinball Life. I'm assuming I'll get the new board like you did since I just ordered it a couple days ago.

I haven't taken any yet, but I will next time I'm in the backbox. It's exactly the same as the old install except the 20V pin needs to be connected to a 20V source.

Photo officially snatched.....Snatched?!?....Oh my.

As promised, here are my pics. Since it's a Whitestar, it might not be as useful as you'd like for Metallica. The red wire is the 20V source that is needed for the new board.

IMG_2311.JPGIMG_2309.JPG

Could you loop the wire from pin 1 to pin 2 on the step up board?

I'm just about ready to install the knocker in my Metallica and wondered why you need to separate the Q24 input from the 20v source when Q24 is a 20v source. Someone educate me on why that wouldn't work or could cause a problem.

Pin 1 (from Q24) is not a 20V source. It is the "source" pin of an N-channel MOSFET. Basically, you can think of it as a switch to GND.

I see now, I was on the wrong track. Thanks for that!

After comparing the manuals it appears that Metallica would use the same connectors and pins as LOTR, they're just located in different positions on the board:
50v from connector J10 'Voltage Outputs' pin 5.
20v from connector J7 'Low Current Solenoids' pin 1.

Confirmed working on Metallica!
The new step up board and knocker mounted in lower left corner of head. Had to move the wiring harness bundle a bit over to the right to clear the coil.
50v from J10 pin 9 through a 3 amp slow blow fuse.
20v from J7 pin 1.
Q24 from J7 pin 10.
Ground attached to metal backing plate screw.

_{Post edited by Paladin: had wrong pin listed for 50v, corrected now.}

Paladin - Could we see an "installed" picture in the head, and pictures of J10 and J7 wiring?

I'm a little embarrassed about the connectors, as they're pretty ugly. I decided to make my adapters with parts I had on hand instead of ordering the IDC plugs and 'Z' connectors that some are using. Everything is working fine, so the theory is sound if you just want to use the photos to see where to hook the wires.

I used standard crimp connectors with trifuricon pins on one end, and for the other I soldered wires onto the end of some header pins. I then covered the header pins in hot glue so there wouldn't be a chance of anything shorting.

I used 18 gauge wire for the J10 connector. I pulled 50v from pin 9 (I've edited my original post above as it listed the wrong pin).

I used 18 and 20 gauge wire for the J7 connector. I pulled Q24 from pin 10 with 20 gauge and 20v from pin 1 with 18 gauge.

I pulled ground from the metal backing plate screw below and to the left of J7.

I mounted the knocker in the lower left side of the head. I had to move the wire harness bundle a bit to the side so it would clear the coil on the knocker. The knocker is fairly far away from the strike plate. I think I could have mounted it closer and it would have helped the clearance.

knocker2.jpg
knocker1.jpg
knocker3.jpg

Could we use this board for power to make it an easier install.

http://mezelmods.com/collections/diy/products/stern-power-tap

Just trying to figure out the easiest way to do this.