When you do, look really carefully at the switches that will be stacked somewhere on that reel. They'll be two or three of them probably. Set the reel manually to "0" (by pulling in the plunger) and then see where the switches are set (open, closed, etc.)... and look at the one next to it, or on the 2 player side, to see how those look. They should all match up... you need to clean them too. If the problem is that the reel TRIES to reset, but can't turn over, then something's probably dirty around the shaft of that one, and it needs to be dissasembled and cleaned.
Keep working through Clay's guide and you'll get there.