Chosen Solution

Hello, My speaker had no sound on the 6s, so I replaced the speaker. But there is still no sound! The headphones worked fine though. What other part(s) can I replace to test?

You could try replacing the charge port, which connects to the loud speaker.

To examine whats actually wrong with it depends on the history of the phone. check if your phone is liquid damage or not, if it’s not WD than change the charging port and it might sort the issue if charging port is faulty, if it still won’t work, than probably audio ic or any component faulty/damage on the circuit board.