Have sound but no vocals on DVD player. What is…

for RJTech DVD Player RJ-800DVX

Have sound but no vocals on DVD player. What is wrong?

Toshiba DVD Player DR430
manual del usuario dvd video grabadora dr430 ku
manual del usuario dvd video grabadora dr430 ku
Pyramid Car Audio DVD Player pd303
DVD Player Automotivo Pyramid PD-303 TV 3"/USB/SD
DVD Player Automotivo Pyramid PD-303 TV 3"/USB/SD
Nesa DVD Player 1002
no sound nesa dvd 1002
no sound nesa dvd 1002
Mintek DVD Player MDP 1770
This unit has never been used, sat in a corner. N
This unit has never been used, sat in a corner. Now, the battery has been charged, Red Box DVD inse…
Pioneer DVD Player 08a06-373-220
8 pin din plug connection
8 pin din plug connection