I have a Gottlieb Big Indian (4 Player) game. At times, the score does not increment correctly in the 1,000's. For example:

With a score of 90, adding 10 gives 100 -- this works correctly.
With a score of 990, adding 10 will make the score 000, not 1000 as it should. With a score of 990, adding 100 will make the score 090, not 1090 as it should.

Certain features of the game score thousands as they should, but only when they directly increment the 1000's reel. For example, the vari-target will score 1000, 2000, 3000, 4000 or 5000 as expected, all drop-targets down scores 5000 as expected, and the bonus count-up works correctly (by thousands).

As noted above, the thousands doesn't count correctly when it is to be incremented by a lesser value score count incrementing the hundreds score from "9" to "0". This function is identical across all 4 players.

I am a novice to repairing these type devices. Although I have only owned it for a few months, I have completed a few repairs successfully, but I just don't know where to begin on this one.

Any thoughts?

Thank you.

Thanks to all who replied!

Rolf,
Appreciate you taking the time to reply. Thank you.