Earpiece is very quite

Hi,

Is the audio level OK when using a headset?

Has the phone been dropped or gotten wet at all?

Some things to try to resolve the problem or to isolate where it may be.

If you haven't already done so (you never mentioned it):

Wipe the cache partition and check the audio level in the earpiece receiver.

Start the phone in safe mode and check. If it is OK in safe mode, then a downloaded app is the cause of the problem. The trick is to find out which one.

Perform a factory reset and check the audio level when the phone is in default mode after the reset. Take heed of the caution notice in the link and also it may be prudent to backup the phone to the cloud or a PC before doing the reset as all your data and downloaded apps will be erased. You can always restore it to what it was before you reset it by performing a restore, using the restore feature in the phone, with the backup that you made earlier

If it is still faulty in default mode then it is a hardware problem. As you have already replaced the earpiece receiver then possibly with the audio codec chip -U808 as shown in the schematics for the phone. (There are other links to the schematics online. This one was just to show the location of the IC).