These displays are sealed (like press fit) and cannot be fixed unless replaced. If all the wiring going through it is OK (although it can be hard to spot because it goes a long way), then I would suspect the display to have taken humidity. Replacing displays must be quite a task and expensive.
I would give it a few weeks under hard sun and try to avoid water on it and then you may find your answer. You will find several threads on this forum with similar issues. On mine, humidity came out after a whole winter in a heated garage.
I think BRP never intended us to use their skis for 20 years as they barely supply parts after 10 years and still want to maintain them!
Benji.