I'd bet it's a hardware thing. Can be some faulty/fried chip, but can also be a loose cable. The internal screen is connected via a special cable directly to the motherboard. But this cable and its connectors are somewhat sensitive.
The crucial question is: does the system still see the internal screen or not? (the screen being just white can also stem from wrong entries in the BIOS).
- could you maybe post a photo of what the screens are showing?
- then, it would be a service call, either to your local Avo hero, or to
repairs@avolites.com.
- only if you are ready to dig a little deeper, maybe you can find out whether windows 'sees' the display or not (Tools -> Control Panel -> Advanced, Display -> change Resolution)