I am sure many of you have experienced the disintegrating coil stops Stern used in their games like ACDC and MET. The symptom you have bad coil stops is a lot of gold colored dust accumulating in the cabinet and longer flipper travel. I just checked my ACDC and the stops are shot. The brass(?) spacer between the plug and the mounting plate is almost completely gone, leaving about a 1mm gap and a wobbly plug. The plug itself is almost brand new looking.
3 of my games probably need coil stops replaced because of this. I wonder if I should ask Stern if they will warranty these since they are obviously defective. I'll try that route first.. I bought 5 NIB in the last 2 years so I think they can cut me some slack here.