I am having an issue with the score reset at the beginning of a game with 1976 Bally Hokus Pokus.

Starting issue:

The thousands wheel on Player 1 only will not reset.
All other wheels reset fine.
If I manually reset the wheel to zero, everything resets and plays well.
While the thousands wheel will not move, the motor can be heard under the playfield, and the score reset relay is clicking away in the backbox trying to reset.

Based on Pinrepair and past Pinside posts searched, I did the following to the best of my ability (I am a beginner):

Cleaned all three switches with flexstone on all four player 1 scoring wheels, and spaced them appropriately.
Cleaned all eight switches on the reset relay, and spaced them appropriately.
Removed, inspected, spaced the scoring wheel switches.
Unscrewed, inspected, spaced the scoring reset relay switches.
There are no obvious wire disconnections that I see.

Then, at one point earlier this week, suddenly the thousands wheel no longer has this problem and is completely repaired. BUT...the tens digit of Player 1 has the same exact issue.

I have been working off and on for a week on this... am I missing something obvious? I appreciate the help and thank you.

I verified via multimeter/clips that the tens switch is opening and closing correctly.

Through elimination (I hope this was safe) I went through all 8 of the score reset switches with the power on and identified which one was the tens wheel on player one using a thin piece of wood. Then shut off the power and used the multimeter - this also checked out as closed when closed.

I pushed away all the plastic protectors around the solder points and what I saw is shown below on the top zero switch. I am a complete beginner with soldering but this did not look right. Could that be a bad solder spot which somehow could be returning a constant open value even when closed? It had a white substance on top which was mostly removed as part of uncovering it.

Thank you for your help.

hokuspokuszero (resized).JPG

hokuspokuszero2 (resized).JPG