Replacement laptop display only works for 1sec after boot

After smashing my old laptop LCD, I ordered a replacement part from a dismantled 2nd hand laptop. I attached the screen, and the first time I turned it on the screen worked perfectly. Since a reboot however, the screen flicks on for around 1s after boot, and then becomes blank / black. No backlight is on and no image is visible on the screen.

If I use an external monitor to change the resolution of the laptop screen using Xrandr, both screens flicker and the laptop again becomes visible for a very short time, before returning to black.

When I plug back in my old smashed LCD, the screen works fine apart from being smashed - it doesn't go black and I can use it normally.

The laptop is a Dell Inspiron 15. Does anyone know what I can do? Is this a hardware issue or a driver issue?

Thanks for the help!