Making alot of noise is one of the best parts of playing pinball, because you know you're scoring. But in many of the older EM's,the foam on which the plungers sit can become worn out completely, causing a thud after activation, or worse yet, become sticky.
I recently was playing a game and the 1000's wasn't chiming. I took out the complete chime unit (which was fairly easy) and noticed the landing foam had become sticky and a plunger was stuck up in the coil.
I took the old nasty foam off and installed beer seal (closed-cell weatherstripping.) Cleaned the plungers real good, and checked for proper action. In some cases it would require changing the coil sleeves and maybe even a burnt coil. You can also check the grommets. Replacements are available.