what do you call those red things painted that are on the side walk that firefighters get water from?
have you tried system restore?
Use a Halon or Carbon Dioxide Type C fire extinguisher for electronics. It will smother the fire without being electrically conductive, and without the messy damage of foam and dry powders.
I agree with Roger. You are supposed to change out a smoke detector every 5 years or so, depending on the type, whether it is air sampling, ionization, or optical. The last ones I bought stated 10 years on them. You would be better off with a new one.