After ensuring that speaker is okay , you may then check or replace the components showed on the solution below. These are composed of filter coils or inductors, you may also trace the audio signal line paths and check if the line is not open or cut.
Nokia 7230 Ringer and Integrated Hands Free Loud Speaker No Sound Solution
If the filter coils is okay and the line paths is not being cut or open, you may then suspect that the problem may lies on the GAZOO IC, reworking this chip might possibly fix and solved Nokia 7230 Ringer and Hands Free Speaker Problem.
