As I approaching the third hour of cruise, the whole aircraft freeze, with some weird indication on the EAD, PFD and ND (the pointers disappeared etc.). But still I can click every controls of the aircraft and the aircraft response, for example, I pressed the 'Z' key, the 'Autopilot Disconnect' sound can be heared, but no indication on the PFD, and I clicked 'AUTOFLIGHT' button and the sound stopped. This happened to me 2 times in a row.
Can anyone explain this weird behavior?
Regards,
Sarun