This solution shows the location of certain components that might get damaged when the IHF loud speaker that does not have an audio sound output when the hands free loud speaker is activated.
Nokia 2710NE Hands Free Speaker Components layout and tracing line paths.
Make sure to have completely check the speaker and found it working okay before proceeding.
Check the speaker terminals and terminal pads that it have a strong contact connection. A corroded and speaker terminal and terminal pads make also the circuit to fail.
Check both the positive and negative filter coil, these are chip inductors that filter the audio signals from the audio amplifier IC. Then check and also the corresponding input chip resistors just located near the audio amplifier chip, these resistors have resistance value of zero ohms. Do a mild re-flow on the audio amplifier chip. Remove and do have a line check to its solder ball bumps to the corresponding components where it is being connected. Try to replace a new replacement audio amplifier IC if all the corresponding components and line paths seems to be okay.