Just became a member and have a strange problem that has developed over the last few weeks. The switch on the inner left loop does not register during game play but tests OK. During game play Tiger Loops from left loop don't register, and left ball lock doesn't activate magnet.
This has crept in slowly over the last few weeks where it was very occasional, but know appears to be permanent. Is this just a diode problem or something more complex.
Hope some one can help.

Didn't test in switch edge mode as I don't know what it is yet. This is my first Williams machine and am still getting used to the menus etc. I found another post with the same prob and states it was the switch not activating when the ball is travelling too fast. I tested it out during a game and the same thing happened. When the ball was slow, it registered fine. So I think your right, I need to adjust or change the switch. Thanks Dan. I'll get to it hopefully in the next couple of days.

After some messing around, found that the problem was the wire not positioned correctly and after many attempts at bending and re-shaping it seems to be fixed. I think it must have been replaced at some stage in its life because the shape of the wire seems backward to the ball travel compared to all the other wire forms. the steep side is on the side that the ball hits first, not sure what difference it makes, but works fine now.
Thanks for the advice.