I recently had 2 x SM57s stop working. Not stop working completely. They sound hollow and lower volume, as if someone put on a low cut @ 500hz or something with the gain turned down slightly. I find it strange this happened to 2 mics at relatively the same time. My other 57s still work fine. I A, B, C'd them all on the same signal path to test them all.
In fairness, the 2 that failed were very old (over 30 years), so I just went out and bought new ones. I can always use more SHURE stickers anyways . They were my 2 original 57s I bought when I was 16 years old, but I don't see why they should fail. They never received any abuse or drum stick hits and rarely left my constant room temperature studio. The only thing I can think of is the diaphragms may have worn out somehow? Any ideas why this would have happened.