Yes when you put a powered logic board in water it will get damaged. Especially if you put power to it before it's had adequate time (days not minutes or hours) to dry.
You can use the tags at the left to find a guide and advice about troubleshooting your problem, but if you've replaced the microphone a damaged connector or component on the logic board is the next most likely cause to your problem. Logic board component repair IS NOT A DIY PROJECT. . . however complete replacement of the logic board is.
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