Hello All

Having an issue with my Bally Playboy and the knocker. I am using an Alltek SDB and according to Dave at Alltek whom I took a video for of the startup, he says it looks good!

What is happening is as soon as you turn the game on, way before it boots, the knocker locks on. I have checked the coil out if the circuit and it is good showing about 5 ohms. I have replaced the diode making sure it went in the same direction as the original. Original was fine but cut it out to test it.

Anyone out there able to shed some light on where I should start checking this issue? Game is really coming along nicely and this is, at this point, the major issue.

I do have a new Alltek light board coming as the MPU are new and the SDB is newer. Just fyi and almost certainly unrelated but just putting it out there.

Thank you as always.

G

Thank you @jethrop. I do not have a schematic for that board. Can you or another point me to which transistor it is please?

Thank you

The reason why I checked the coil is because those with far more experience than I have suggested verifying that the coil was not shorted and also checking the diode to insure it was ok. Hope that clears that up

Appreciate all those who were really helpful in their responses. Thank you. I’ll have to dig into the SDB a bit further. Thing that is confusing there is that I shot a video of the startup sequence to Dave at Alltek (very helpful) and he advised that it appeared to look correct. That is the solenoid status leds. Just a bit confused as if there was a problem other that board, I was under the notion that it was pretty intelligent to show that there was an issue

I fully get the idea of a driver transistor and how it works. Further understand that if it is shorted it will no longer “switch” but send current that will result in the coil be locked on. Again just a bit confusing when I have the manufacturer telling me it looks good. I’ll do some more digging and get to the bottom of this.

Again fellas, thank you for your thoughtful and helpful responses. I am grateful

Absolutely makes sense. Thank you JethroP !! I am going to check and see if the coil is somehow shorted to ground. Barring that, it must be an issue with a driver transistor on the SDB

Thank you again!

Thank you fellas. I am sending the board back to Dave at Alltek to eliminate that from the equation. I will also verify the coil resistance again and get a new one if needed. I remain grateful to all. Thank you

Thank you again phishrace !! Rechecked the coil and it is indeed the correct one according to the manual and it is showing a resistance of 10.6 ohms. So I think we’re good there. Must have fricked up the reading before. My apologies.

I also checked to see if the coil was shorted to ground somehow and it is not.

I’ll wait to see what Alltek has to say. Hopefully they find a mosfet that is bad and that will put this small issue to bed.

Thank you all!

G

Hi Fellas

Ok think I MAY have found the issue and was hoping j could get some confirmation. Please see the attached picture.

If my suspicions are correct, I have the knocker wire (black with white trace) in space 4 of J2 on the SDB. Think this should be in soace 5. Can anyone out there confirm please?

By the way. I did send in the original SDB and now have the replacement in the game. Soni do not think I have an SDB issue. Thank you Save Seidman at Alltek

Hoping you guys can set me straight here. If this is indeed correct what I am thinking, this is the last issue!!

Thanks guys

George

FA212681-5E03-4A51-A50F-C918C18026F6 (resized).jpeg

Shit. Now that I look at it closely it IS in the right spot. With the SDB board being exchanged by Alltek, I am at a loss. Sorry guys. Thought I may have found it. But it is in the fifth spot.

When I put my meter on the black wire with white trace and the other probe on ground I get continuity. Should not be the case unless Q3 on the SDB is activated or if it is shorted which I don’t believe it to be as this was the same issue I was having before and now with a new board.

Again guys any guidance would be appreciated sorry fir the false alarm on last post

Just fyi, Alltek did not say what they found if anything.

Thank you for replying slochar
I did the first test you suggested by testing for ground on both coil conductors with J2 disconnected. I DO NOT get continuity

As for the coil and wiring, the two green wires are going to the banded end of the diode (+45.6) The black with white trace to the other terminal.

There are no screws running through the coil and I did ohm out the coil and it was ok at approx ten ohms.

Thanks again slochar
Ok. Put probes on J2 Q3 terminal without connector on and other probe to ground. Even without turning the machine on I got continuity. This happened with J4 off as well

Continuity that is between J2-5 Q3 and ground. Sorry fir not making that clear

Here is a pic of the new board in the game. Screw in upper right and lower left corner to affix board. No plastic standoffs

image (resized).jpg

Given that I do not have any plastic mounting clips on this board, just two screws in the corners could the board be shorting against the two rails it’s mounted to??

Well here is what I got (doesn’t sound good) I held the board in the air not touching anything and then checked for continuity between ground and J2-5 (Q3) and yeppir there is continuity.

As I have said before when this issue reared it’s ugly head, the knocker would lock on instantly upon game power up. After initially finding this issue we disconnected the ground wire to the coil so that nothing would get hot.

I will email Dave Seidman at Alltek and see if my bird that I sent in had a bad Q3. There was no report with the board I got back just a different bird soni don’t know.

Perplexing…

G

Have emailed Dave at Alltek with the hopes that he can shed some light here. Just cannot figure out how Q3 would get blown as the knocker has been disconnected and only tries to connect a couple times to see if I still have the issue. When I realize I do I immediately shut the game off so I am not stressing any component by leaving it actively locked on

Maybe the below will help. I followed vids guide to est the Q3 and then Q19. This is what I got

409F8CBA-311A-4BC9-A943-993DD376234D (resized).png

To answer your question about whether the wires seem crunchy”. No not at all. I understand what your asking and further the feel of a wire and insulation that has gotten really hot. Hope that helps too.

As fir the continuity question I am using the tone option on my meter

image (resized).jpg

Again, when the new board was put in, the knocker was disconnected and only briefly connected using test leads. When it locked on I immediately shut the game off. I did not leave it in this condition for more than a second or two at most

Just talked to Dave at Alltek and he advised that there was nothing wrong with the previous board I sent in. Hmmmmm. Now j am really confused

Just to recap; Connectors on J2 and J4 are disconnected. Board is floating not connected to rails by screws etc. when I place the meter on J2-5 and the other lead on the ground strap I am getting continuity when the game is off.

When I check for continuity between knocker coil terminals and ground, I do not have continuity.

Thanks for all the kind assistance thus far guys. If you think of something, please let me know. Thank you

George

Hello @quench. Thank you very much for the assist. I will look here in a little bit and confirm. Let me get the wires correct first on the SDB and then go back and revisit the continuity situation as the fricked up wires could be causing all this. Hang tight and I’ll be back with you soon. Thank you again!!

Three cheers for Quench !!!

That was it. Damn, something so simple. I am sure that I messed that up as I re-pinned all the molex connectors. Thought I paid pretty close attention. Don’t know if that was working before I got the game but bottom line is it is now. Thank you Quench and all who helped in this, at times, weird problem. Thank you all!!

George

Thank you @quench. Without your direction I would still be hunting around. Thank you!!

Thank you for the kind words. I am grateful. As I said before, I was very careful when I was re-pinning so it could have very well be my mistake or it could have been there all along and I just duplicated what was there even though it was incorrect. Good thing is that issue is no longer an issue and the game is very close to being perfect. Still a couple things to dial in as usual but very close. There is NO WAY I could have fixed that issue without the great guidance here on this thread> Thank you fellas!!

G