Visio master pro 510 A201HT, screen problem

[Micha]

Hello electrical engineers,

I have a vision master pro 510.

There is a screen/brightness problem.
It’s chancing from bright to dark during operating.
The brightness on the monitor and onboard is working fine.

Does any one know what component is responsible fore that?

I din’t find on the forum.

Greetings from Holland.