Quoted from SDTMinSTL:
So I am reaching out to ask for some help. I have been chasing an issue I keep having with balls becoming magnetized. I have searched and searched on pinside and I have done the following
Trying to think through the problem for root cause, and I wondered how all balls could get magnetized after only a small amount of games. It usually takes a while...
Then I thought - where do the balls hang out a lot? The trough. Google search showed someone else with this problem recently. Some suggestions there, but I would go further and try to find out how the trough gets magnetized, if that is the case.