Chosen Solution

Hey guys, I have a phone repair lab and recently someone came with an iphone 8 that the bottom speaker isnt working, but the top one does work. ive tried replacing the speaker, replacing the chargin port, even changed his audio ic and nothing seems to work. maybe someone knows why is this happening?

Firstly it is always good to know the history of the phone especially when it comes to audio problems. ·         What was the phone doing before the sound stopped? You should have left the audio IC alone as you have just created a variable in your repair. The audio IC decodes and encodes the sound, since you said top speaker was working I would be looking at the speaker amp components. You need to diode the dock connector there are filters near it that could have been nudged or blown. Check for open lines on the speaker amp circuit. If you have ruled out parts that is where the problem should be.