If this is your case, come and check this post greetings ... https://yoreparo.com/tv/televisores/tubo/preguntas/901245/para-saber-modo-de-servicio-de-tv-cyberlux-tvfscx-21jp
Entering service mode ..
apply the following.
6483 menu, mute M2 screen.
set up select 1.
Then apply the actions.
mute +6 + mute +6 + mute until the menu came out.
of adjustment geometry.
v size,
v position.
v line
Friend if your problem was solved, comment to help other people ... thanks and regards ..
brother if I qualify as an accepted solution is xq solved the fault with the information you gave me. Thanks a lot.