This must be happening to a DH a friend of mine has. It has been having issues with the magnet not always grabbing the ball. I believe this is because of the placement of the opto bracket and the beating it takes.

I realize the thread is old. I'm posting to add to the archive to assist someone that searches for this specific problem -- like I just did

My buddy had a DH years ago and it had the same issue you show in the picture with significant junks out of the playfield.

I just picked up a DH and among other minor issues, it has the "magnet broken" issue. Of course, to get to that you have to take the damn game apart. My playfield, thankfully, doesn't have the wear and tear yours does; however it has a divot in the playfield and the same beating on the opto bracket. I'm thinking this is a design issue.

Not sure how to resolve the issue. I see how the opto bracket is getting smashed. The ball is launched from the shooter and I suspect it is hitting the bracket. I will likely put some mylar on top of the magnet area. Might even get a bit more creative. I've only just found the issue. I'll follow up if I come up with something.

Anyone that buys a DH, I suggest you take it apart and look at the magnet. In my case, it is really mushroomed to the point that the ball is getting caught on it and I'm sure it would start to cause problems if not corrected.

Cheers,
Duane