Earspeaker after displayrepair extremly quiet

Hello everyone,

I repaired an iPhone 4s the first time. I had to replace the display. After I used a diagnostic app, I called from another phone and the earspeaker was so silent, that I could hardly hear anything. Some other people encountered this problem before, but non of the solutions worked for me. I now completely disassembled the iPhone and put the earspeaker on the logicboard, started the voice memo app and switched it on the earspeaker. No effect, it is so silent. I know ask the experts wheter I should buy a new earspeaker.

Thank you in advance for useful answers