Given that it was previously repaired, I would suspect a loose cable first.
Other electronic or screen failures might also give those symptoms, but start with cables.
Disconnect and reconnecting can solve issues associated with the cable or connector.
I would do it a couple of times for each cable, then check the result.
If it is not that, the next item would be the main board. Then the screen.
Those items may not be economically viable, considering cost and warranty.