I would never have believed this could cause so many problems if I didn't just go through it. Even if the sanctum looks good, it could have enough of a divot to cause the ball to hang up. Just an extra half a second stuck on the sanctum is enough for the machine to miss it as it passes the optos the second time. Plus, if it misses it in this way, it will throw all sorts of other errors at you too, like the wall target is bad, etc. that have nothing to do with your problem. It's a confusing cycle.

You can set your playfield steep and see if it fixes it. I ended up cutting a couple little circles of painters tape and putting them under the sanctum sticker. Just elevating the magnet area so the ball rolls faster when released fixed all problems for me.

Does everything check out in the magnet test?

The shape I found best for building up that area with mylar/stickers, etc. is below. That way it allows the ball to roll off very easily. Just a temporary fix though, and I think you're looking for a more permanent one.

shape.jpg

Yeah, oriented like the picture. I used an exacto blade to cut that shape out of about 4 layers of painters tape and stuck it down under the sanctum sticker that someone here made. I kind of wonder if what's happening is more common than people let on. My sanctum was repaired before I owned it - I'm sure it was completely flat after the repair, but over time whatever material was used in that area must have compressed between the ball and the magnet. So if the repair isn't 100% solid, the problem comes back pretty quickly, and no doubt quicker than the original playfield wear. I'm too lazy to tear mine up again, so leaving it be for now.