My player sdhowed similar symptoms, It would work as usual for a short time and then the buttons would not work anymore, but the screen continued, and the ethernet connection also continued to work.

After a while, the buttosn stopped wortking alltogether (IR also stopped working together with the buttons)

Carsupport tought it might be the displayboard-pic, and a replaced display board fixed it.

Marius (Escort Cab + Mark II)