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(Topic ID: 180282)

How can knocker reset my game?


By mcklit

3 years ago



Topic Stats

  • 20 posts
  • 12 Pinsiders participating
  • Latest reply 3 years ago by mcklit
  • Topic is favorited by 5 Pinsiders

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#1 3 years ago

Hi,

Picked up a BSD that needs renovation.

When opening the backbox I found that the knocker was disconnected. I reconnected and started the game. When the game ends and I might be lucky to “win” an extra credit, the knocker fires. But when the knocker fires the game will “reset” but only so far. So whatever number of credits I was holding before the knocker fires and the game resets – will still be there. In other words – it’s not a “total” reset like when the game boots.

Any ideas about what I should look for to make this go away?

Thanks for your feedback !

#2 3 years ago

Check the diode for the knocker (it will be on the driver board). Also check the resistance of the coil.

#3 3 years ago
Quoted from gutz:

Check the diode for the knocker (it will be on the driver board). Also check the resistance of the coil.

Checked - but no problem here. Diode works fine and coil reads 4 Ohms (23-800).
While I had the board out I also tested the transistors and resistors along the path from the connector (J130) to the LS374. Also reads out fine !?!

Anything else I should try to look into?

Thanks !

#4 3 years ago
Quoted from mcklit:

So whatever number of credits I was holding before the knocker fires and the game resets – will still be there. In other words – it’s not a “total” reset like when the game boots.

When a game boots, it still has any remaining credits on it.

Go through normal reset issues - http://www.pinwiki.com/wiki/index.php?title=Williams_WPC#Game_resets

LTG : )

#5 3 years ago

Thanks for the link.

I went through the different steps but they all looks ok.
I didn't replace the capacitors - but if needed I'll go ahead and make it happen.

But - the items on the list seems to relate to general reset issues that can happen at any point in time. In my situation its specific to firing the knocker in the back box. Other than that it just keeps playing without any reset. Yesterday I de-attached the knocker and then nothing happens when the knocker fires. So it's "something" that happens when the coil is attached and activated.

I don't have a second solenoid that I can try out. But maybe I should get one? The solenoid itself does not have a diode - like I see on the flipper coils. I know that it has been moved to the board and I also tested it - just to find it working. Should I try soldering a diode on the solenoid anyway?

Thanks!

#6 3 years ago

It won't hurt to fit a diode to the coil BUT make sure the banded end of the diode faces the supply voltage terminal - the one that has the 50V applied all the time.

This can't be measured with a meter because both terminals will read pretty well the same.

Trace the wires and make sure you get it the right way around or POOF!!!

#7 3 years ago

Remove the coil from the bracket and examine closely. Sometimes the wrapper on the coil wears againts the metal and grounds out causing resets when energized. Seen this on knockers,kickbacks etc before. I usually wrap a couple of rounds of electrical tape around the coil and all is well. You may want to check the fuse for this circuit as well as it may be over fused.

#8 3 years ago

Does the machine reset if you fire the knocker in coil test mode?

#9 3 years ago

Sorry for the late reply.
Had some other things I needed to take care of in the game before I could go back to facing this issue.

So I tried testing in game and with solenoid test mode. Both ways will make the game reset. I tried changing the solenoid - that did not help. Also tried installing a diode on the solenoid - also no luck.

A strange thing to note... I inserted the plumber upside down - having the plastic end facing down instead of up. That made the problem go away !!!!! Can't explain why. I then changed it back with the plastic end of the knocker facing up - and the problem came back. Don't know if it was by chance the problem disappeared with the plumber in the wrong direction or not. Have not tried making it face upside down one more time to see if the problem will go away again if I do so.

#10 3 years ago

Could be vibration-related. I had a Diner that did this. I tapped all the chips in the MPU to figure out which one was causing the reset. It was the main ROM in my case. Reseated it and problem was fixed.

#11 3 years ago

I have an Elvira that reset when the knocker fired, I had a splash of solder on the main board that somehow seemed to be the cause.

#12 3 years ago

Remove the plunger from the knocker and see if the problem still occurs.

#13 3 years ago

Tried to remove the plunger and now there is NO reset ! I can hear the coil being energized but the games stays on. This is true in game modes as well as test mode.

dangerterror - how did you figure out that the problem was vibration related? After taking out the plunger it took a hammer and "slammed" it into the top of the backbox. But that did not reset the Pinball. Maybe it takes a "certain" kind of knock to make it reset?

#14 3 years ago
Quoted from mcklit:

it took a hammer and "slammed" it into the top of the backbox.

Oh man, a hammer?? rubber mallet, right?

#15 3 years ago

I had the same issue with W?D. Started happening when I put in a new game ROM with the latest code. Swapped out the ROM for another one, problem went away. Not sure if the ROM itself that was causing the reset (bad burn?), or if it was a vibration issue.

#16 3 years ago

If she leans on the start button after ball one it can reset.

Sorry. Just could not believe no jokes yet.

#17 3 years ago
Quoted from mcklit:

But that did not reset the Pinball. Maybe it takes a "certain" kind of knock to make it reset?

Yes it could be a vibration in a specific location and angle of attack. Use a rubber mallet and duplicate the way the knocker strikes.

Inspect/seat all cables and socketed chips and make sure none of them are loose.

#18 3 years ago

I had a knocker reset on a T-2 I owned and removing the plunger made the problem go away. A cold solder joint on the cpu ended up being the culprit and the vibration from the knocker set it off.

#19 3 years ago

Did a ton of test and parts replacement. Thanks for all the good ideas you all came up with for testing !!

arcade Thanks for cracking the joke. It was needed

Anyway - today I got hold of a spare power board. Once installed as replacement for the original PB the knocker problem stopped !! As suggested in some of the replies above the problem loops back to a loose connection, a cold solder joint or something similar.

So - the hunt is on. I need to find the "problem area" and get i fixed.

I'll close the thread and mark it as solved.

Thanks !!!

2 weeks later
#20 3 years ago

Also check out this topic where the cause of the problem is found and fixed.

https://pinside.com/pinball/forum/topic/reset-problem-again#post-3639151

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