[Olop]

Mine was working but after yesterday's charging, suddenly there's no sound from the left earpiece. I charged it for 2 hours only so I don't think I had overcharged it. I tried to resolder the output jack and a few other parts but its still the same. Tried with other earpiece and its the same.
 
Can someone help advise how to solve this? Thanks a lot in advance.

 

[bagman13]

Do you have a volt meter or a function generator or a oscilloscope? Any of these will help you fault find.

 

[Yoga Flame]

Agreed. And the initial checks on the Mini³ website are a good place to start.
 
Try reflowing R5L, R1L, and L1L if you have not done so already.