Acer Aspire 7250 Black Screen

Good evening, I have a problem with an Acer laptop model Aspire 7250

The laptop powers on, the disk spins, the fan starts, but there is no display on the screen. I have tried standard troubleshooting steps (removing the battery, testing the laptop with and without it, removing the BIOS battery, putting it back, performing a CMOS reset, connecting the laptop to an external monitor using an HDMI cable and a VGA cable, testing the RAM sticks on another PC (they work fine there), putting in another stick, disassembling the laptop and removing and reconnecting the screen cable connector)

Absolutely nothing works

What can I do to solve this problem? Because I’m starting to lose patience...