Why my speakers do not work properly?

While I was planning some music on my JBL Flip 4, the speaker's sound suddenly stopped. I thought it was something normal, I turned them off then on, but this time no sound at all even turn on or turn off tone. I did a successful speaker reset, connected it again to my phone and laptop without any sound! It charges will, connects well through Bluetooth except for no sound. I didn't drop them or used them in water (although it is waterproof). Help me please, how I can fix that? My warranty has ended.