My father owns 2 Play 5 speakers. I recently had a close look at one of them and noticed that static noise was coming from the right tweeter whilst the other was working perfectly fine (the white noise continues even without music). I then decided to look at the second play 5 too and noticed that both tweeters on the second play 5 were just not functioning properly. They both sounded very quite and made a consistent very very silent low frequency ticking noise. I am quite experienced with electronics but not with a speaker system. I can replace the parts but I first need to know which are broken. Can anyone help with identifying this?

Thank you for the help and hope to hear from you guys soon.