Caller can’t hear me when I’m on speaker

Hi @candacejon22442

Try using the phone in safe mode and check if you can be heard when using the phone in speaker mode.

If you can then a downloaded app may be the cause of the problem. The trick is to find out which one is the culprit.

You will need to uninstall each downloaded app one by one and then test the phone in normal mode to see if it works OK or not. When it does the last downloaded app that was uninstalled was the cause. A downloaded app is one that you downloaded and installed and didn't come pre-installed with the phone.

If still no good in safe mode then there may be a problem with the microphone that is used when the phone is in speaker mode. This microphone is not the same one that is used when using the phone in normal mode. - see image below

It could also be that the voice inlet hole for the microphone is blocked with lint etc.

Try using a vacuum cleaner and check if this clear any obstruction in the hole. There is a water resisting gasket between the microphone and the voice inlet hole so trying to clear it with a pin etc will only push it further in

If still no good then the phone will have to be opened and inspected as to what the problem may be.

Here's an image showing the location of the microphone, the microphone on the systemboard and then the protective gasket when the board has been removed.

Here's the ifixit Samsung Galaxy S8 Motherboard Replacement guide that may help to gain access to the microphone.

if the microphone is faulty search online for 3003-001244 to find suppliers that suit you best.

Since the microphone is soldered onto the motherboard, you will need smd soldering skills and tools to perform the replacement. Alternatively, contact a reputable, professional mobile phone repair service and ask for a quote to fix the phone.

(click on image)