Forgive me for another JM hand thread, but I couldn't find anything that dealt with my specific problem. A little background first. About 2 months ago I started getting some screeching from the hand. I replace the x and y nuts and regreased the gear box for the x motor. Put it back together and everything worked great for over a month.

Suddenly, now when I put the ball in lock the hand moves all the way to the right all on it's own. Once it can't go any further it pops the ball out of the lock and into the glass. The error I see in diagnostics is X - NO PROGRESS. In edge test the x opto on the rod registers just like it should. Opto wheel blocks opto it is closed, when the wheel doesn't the opto is open. The X Home switch also registers fine. I don't see anything else that monitors x movement.

It passes the hand test without any issues. The glove moves smoothly. All optos and switches associated with the glove movement work fine in test. I'm stumped? I'm hoping someone smarter than me has run into this before. Any suggestions?

I'm thinking your suggestion is probably where I'm heading. The only thing I've tried with the boards so far is to reseat connectors. The board attached to the x motor with the opto on it is called the position encoder board. I'm completely guessing that the problem is somewhere on that board given its name. Even though the opto registers fine I guess it is not delivering the position properly??? Does that make sense?

Has anyone removed this board before? It's not screwed in place. It looks like it is popped over some metal pegs. Just seems like the possibility for breakage/damage is pretty high when removed.

Luckymoey was on the money. I'm not sure what exactly fixed it, but the dual relay board under the playfield seemed to be the source of the problem. I took the board out and reflowed some solder. I also noticed my connectors are pretty wobbly. I'll be replacing them shortly. When I put it back in and made sure the connectors were well in place the glove went back to functioning normally(knock on wood).

The board seems really susceptible to vibrations because only 3 corners of the board get screwed into the underside of the playfield. The fourth just hangs in no man's land. The two relay boxes are also somewhat large and hang down off the board. I could see how years of gameplay vibrations and gravity could cause issues there. I read some older threads that mentioned this seems to be a common JM issue. Now, I'm off to make a long distance phone call.

So my problem came back after about a week. I didn't fully believe that my random monkeying with the relay board would completely fix my problem.

What I noticed now was that when I went into hand test the numbers used to indicate the hand's x position were not working properly. I would manually twist the hand towards the matrix the numbers would only alternate between 0 and 1. Those number should be steadily increasing as it moves to the right. I pulled the encoder board off, cleaned, soldered, and now the positioning is working correctly. There are two optos on the encoder board. Maybe one was working and the other wasn't? That would possibly explain why the opto appeared fine in test, but no luck during gameplay? Anyway, it's working again, and that makes me happy.