Yep. That's just Data East pop bumpers. They're the worst.
You can re-gap the spoon or file with a flex stone, but don't expect the snappy action of Stern pops.

So here is the trick I did on my DE games and capcom games. Besides cleaning contacts and adjusting them, replace the spoons with Williams spoons. Williams spoons are a bit shallower, and therefore provide more action.

Isn't there a pretty good how to online?

Aren't data east pop bumpers controlled by the driver board? (not sure which generation we're talking) Sanding non-high voltage contacts will just damage them, and it's not going to effect it anyway, as it'd just be a binary on/off signal.

Yeah, those are SS switches. They don't carry any current. As long as the bumper is firing at all, then the switch is clean. Make sure the spoon is pressing against the skirt, and the skirt is in the center of the spoon, and that the contacts are as close together as possible. If you can see a gap, they're too far apart

I second dsuperbee's method! When I first got my Tommy machine the pops were very weak, (the bottom one would hardly even go off). After adjusting the leaf switches to be closer and getting new spoons from Pinball Life (with a more conical shape that centers the pin better), the pop bumpers have been excellent. Here's video proof!

The spoon 'handles' on DE designs are much stiffer and are "U" shaped compared to the flatter and more flexible B/W design. This makes the B/W design more sensitive. Grind off the sides of the "U" on the DE spoons or use B/W parts. DE pops can be really good!

Don C.

so HOW was it resolved op?