Why my my speaker is doesn't working?

try to do hard reset

if it doesnt help take it to the warant

HTC is nout user frendly like Samsung or Apple and doesnt allow u to change softwer very easly. Your problem is in Softwer or Harwer, partly u can fix Softwer problem with hard reset but like I said u cant easly change Softwer on HTC by your self. It requires unlocked bootloader and root. Once u unlock your bootloader ou have no waranty anymore.

Hope it helps!

Cheers