Hi Priscilla, as you say, it is very feasible that the belt that is responsible for opening the CD tray is stretched
it is not easy to access to release the mechanism
I suggest you consult a specialized technical service
I hope you can solve the problem
Greetings Franco Dosil

Hola Priscilla, por lo que comentas, es muy factible que la correa que se encarga de abrir la bandeja porta CD, se encuentre estirada
no es sencillo acceder para liberar el mecanismo
Te sugiero consultes un servicio tecnico especializado
Espero puedas resolver el problema
Saludos Franco Dosil
https://www.manualslib.com/manual/520425/Toshiba-Sd-K220s.html