Yes . you are correct, fault con be coming from Video card, LCD cable and LCD as well
Trace it,
* Check the graphic configuration set it to default level and see whats going on if same fault observed,
* Connect you M17X to external Display and check any sign of flickering
if yes - fault coming from your Graphic chip
if no - you can determined LCD or Display cable make the trouble and both of coming together and you can the Display with cable