Refer to the solution below for it shows the basic and most common parts or components that if damaged will probably result to headset audio failure. This solution provides the location of the components that holds for headset microphone and earpiece speaker circuit components.
Nokia C3-00 headset no sound can be heard problem solution
1. Check and try using another working headset.
2. Check if the headset is activated on the audio enhancement settings
3. Visually check the headset jack connector, clean if oxidized, replace if damaged.
4. Clean the headset jack terminal contact pads on the PCB board.
5. Check replace the filter IC's of the microphone or earpiece speaker corresponding.
6. For headset ear speaker problem, check the filter coil and apply the jumper remedy of the filter IC.
7. Check the VBAT 3.8V. Replace the ear speaker audio amplifier or controller IC, if the battery supply voltage is okay.
8. If the above solution doesn't solved the problem, the possible faulty is the power IC. reworking or replacing it will only fix the headset problem on your Nokia C3-00 repairs.