VGA Display issue

[zoronoa02]

Hello, my problem is that I want to convert a laptop into a recreational machine and I need the image to be reproduced on an external 4: 3 screen by VGA, recalbox recognizes it, but does not connect or remove the video signal directly by removing the cable, If I do that, only the initial charging and terminal screen is reproduced on the external monitor. Does anyone know how to fix it?