GS, welcome. A good receiver with reasonable clean power capabilities, say anywhere in the 100 watt area, should drive those speakers at all safe(to your hearing)levels with no damage to the tweeter. Your suggestion of a possible bad capacitor(in the speaker crossover)would allow bass frequencies through to the tweeter and damage it. That's a good guess and I don't have a better one.

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Enjoy the music, not the equipment.