Finally got some time over Christmas to get my Metallica up and running again after adding a few mods . I'm having a very weird and random ( although it seems to be doing it more now than it was ) issue .

The problem is that the shooter lane auto-launch sometimes fires the ball which will jump the small wire guide and end up straight in the right hand outlane and drain . Very frustrating .

I've checked the mechanism under the playfield and it's all tight , the wire guide is not sunken into the playfield etc.

I've tried to see what's going on in test mode but it happens so quick you don't get a chance to see what's really causing it . A super high speed / slo-mo camera might help but I don't have one unfortunately .

Has any one else had this issue with Metallica ( or any other Stern for that matter ) and if so what was the cause / solution ?

Thanks for the tips guys . I'll check it out today . Drewblood419 great idea with the brass bush . If I can't fix the problem by adjusting the prongs I'll try that . Should be able to knock one of those up myself easily on the lathe at work .

I'll report back and let you all know what I come up with as a solution .

Problem fixed !! (hopefully .. )

Had a good look at the auto-plunger and found that with a ball sitting in the shooter lane it was touching the prong on the right ( from a player's perspective ) but was not touching the prong the left . It was only just missing it and had to get my head on the correct angle to see it , hence why I didn't pick up on it before . I "bent" the left prong sideways ( towards the right prong) slightly so they both made even contact with the ball .

...*** when I say "bent" the prong , it didn't really need bending as such , more just a slight bit of pressure on it . Would've only moved it over by 0.5 a millimetre , if that . ***...

In saying that it is a bit of a bad design with the whole auto-plunger in the fact that both hinge points for the prong arm are on the same side . The weight of the prongs tends to make it sag quite a bit . Drewblood419's brass bush fix above would remedy that and it's something I may end up doing when I get some time . The mechanism would've been much better with a hinge point on each side of the prong arm .

Thanks for the tips guys , much appreciated .