How can you tell if in-ear headphones have been tampered with?

[Nano0806]

I have a pair of in-ear headphones, Sennheiser MX375 to be more specific and suddenly the left earbud stopped working and i opened it to see what is wrong, the wire that connects the coil is broken.
But then i realized they still have a warranty.
If i return them will they be able to tell i opened that earbud? Are there any seals or things like that? I didn't use any tool, i just popped it open

 

[Cons29]

well, in the first place you should not have opened it.
anything with warranty, if you open it (if it is not to be opened) then you won't get warranty.

just try, and hope they fix it for free.