when I open my pc,the screen is black

Hi @asmamaweyayu123 ,

Just verifying that you are operating Fn + F7 (both together) to step through the display options - laptop display only, external display only or both displays on together, to check if there is a display on the external monitor.

Is the HDD indicator light turning on?

If you do get a display on the external monitor after operating the Fn + F7, try shining a torch at an angle close to the laptop screen and check if you can detect an image at all when the laptop has powered on. It will be very faint so try it in a darkened room to help see it if it is there.

If you do detect an image on the laptop screen, then you have a backlight problem.

This could be caused by a faulty backlight power supply from the motherboard, a faulty backlight cable (or cable connection) between the motherboard and the display panel or a faulty display panel.

Have you tried pressing the Assist button, when the laptop is off to check if it boots into the Vaio Care Rescue mode and the screen works?

What is the full model number of the laptop?