No need to put coins in my Gottlieb Jungle since it clacks random credits on slings and spinner.

I cleaned up the match unit (00-90 unit) and the stepper seems to be working free.

Cleaned all the contact copper a few times to no avail.

If I unplug the match unit no more random credits.

Ant ideas?

Bud

gottlieb-em-pinball-00-90-match-unit (resized).jpg

I took a look at all the contacts, but no affect.
Did some more work on the 00-90 unit with the F relay cam contacts. (there was excessive sparking when 10s scoring)
I moved the pressure leaf on the top so it was not shorting. (it was between the 2 contacts)

I did notice more intel about the issue:

Only occurs on player 1

When it occurs the 10s value is always the same.

Otherwise the game works 100%

Is there anyway I can remove some circuit paths to narrow the search?

Bud

Rolf,
Yesterday I spent about 3 hours chasing this issue.
With the play field up I tap any 10s scoring switch like spinner or bumper.
I watch the score motor and it is not moving when the knocker fires.
About the only movement I see is on the 00-90 unit and the alternating relay under the play field.
(and the player 1 score reel of course)
The knocker does not fire improperly on players 2,3, or 4.
The proper credit knock does occur when the programmed high scores are reached.
I'm usually OK with tracking down electrical faults, but this one is tricky.
Going to try HowardR's idea next.
Bud

Well, I could not get to Motor 1B easily, so I pulled the player1 tens score reel.

I did not see any smoking gun there, but I did nudge a contact here and there.
When I put it back in the random knocks seems to have stopped.

So, my guess is that the tens unit had something just a little off.

Thanks to all for the help.
Now I need to set this for free play since I was spoiled by the free knocks.

Bud