Surface laptop 4 1951 no disp backlight on

[giliy52480@degcos.com]

This surface laptop had a backlight flickering. I put some heat on the edp socket and some capacitors around (I think cold solder occurred) the socket, but after some days the problem came back. Then, immediately after turning it on, the system firmware update appeared(black screen with bar ), and during the test(press hand on the socekt) for the edp connector, whether it was broken or not, the system turned off (because when press on camera socket the backlight is got ok) and finally, when it turned on, the backlight was on, but no disp. When I pressed the F4 key to go to the bios, the display had some horizontal line on the screen with a backlight but no disp (the picture enclosed) and the CPU got warm. This line's place changed after the restart.

I programmed the bios chip with some file from this website but nothing was changed.
could someone help me ?!

[off 366]

Hi giliy
Check the EDP Socket and Display Cable:Ensure there's no cold solder or physical damage to the socket or cable.Test with an External Display:Connect an external display to determine if the issue is with the internal screen or cable.Re-flash the BIOS:Use an official BIOS file from Microsoft's website.Inspect the Motherboard:Look for damaged capacitors or resistors near the EDP socket.