That switch (the one right behind the Newton ball) has to trigger when a ball is present in the sarcophagus, both when the sarcophagus is flat and also when the sarcophagus is lifted to accept a ball from the ramp. If you do a switch test, what you will likely find is that the switch is registering when the sarcophagus is flat, but is not reading when the sarcophagus is in the lifted position. During game play, when the ball drops into the sarcophagus from the ramp shot, it doesn't sense that the ball was loaded. It then cycles the sarcophagus to drop the ball back under the playfield.

You have to adjust the switch so that it reads in both positions. If you remove the plastic on top of the sarcophagus, it makes it a lot easier to do your testing. If you have a flaky switch, you may have to remove the sarcophagus mechanism and replace the switch.

Hi Angus. Please re-read my post. There is only one switch in question, #62. This is the one right behind the newton ball. The switch is most likely working. The problem is that the switch has to sense that a ball is on it when the sarc is in it's flat position (which it probably does), but it also has to sense that a ball is present when the sarc is lifted in the back to accept a ball from the ramp shot. The position of the sarc changes where the ball hits the switch tip. The switches on the LE's are an early design where the tip almost comes to a point at its highest point This leads to the problem where it's only being triggered when the sarc is flat. The arm on the newer switch design has a longer, flatter top which allows it to be more easily triggered when the sarc is in different positions.

I would recommend that you try your switch tests again. I'm pretty sure that you are going to find the switch is not being triggered (or is intermediately being triggered) by the ball when the back of the sarc is lifted up.

Edit: Angus, my apologies. I mentioned switch #62 a couple times and I was confusing that with switch #39 or #40 (whichever is the one right behind the newton ball). #62 is the one on the sarc mechanism disc that senses the back of the sarc is down and under the playfield. If you are getting confirmation that all 4 of the switches on that disc are operating correctly, not sure why you would get an error regarding #62. However, I'm not sure that the behavior of not locking the ball during play has anything to do with switch #62. #62 shouldn't be triggered until a ball is unloaded from the sarc. I had the same issue as you. When the ball dropped into the sarc, the back of it would immediately lower and put it under the playfield to be ejected out from the ramp. Would never lock the ball. The switch right behind the newton ball worked fine, but it would not sense a ball when the sarc was in its loading position from the ramp. I replaced the switch with the new design and never an issue since. There were no error for the switch because it would get triggered when sarc was flat.

The mech has not been upgraded, but the switch arms are a different design. Instead of the highest part of the arm almost coming to a point, the highest point of the arm is flat and longer on the new design. It allows the lower switch to not have to be in absolute perfect adjustment. The ball can be sensed much easier no matter which position the sarc is in. There is a pic somewhere in the thread. I'll find it and post the pic.

The switch on the right has the original factory design arm that most LE's came with. It comes to a point which makes it hard to adjust so that it senses a ball when the sarc is in different positions.

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The switch on the left has the new factory design arm. It's flat at the top instead of coming to a point. I changed to the new design and haven't had a problem since.

If you look at how that switch has to be triggered when the sarc is in different positions, it's pretty easy to see why the new flat design works much better.

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