This happens alot on laptops as they age.
It is wear and tear on the cable that feeds the digital video signal to the screen, and also the power from the inverter board to the back light of the screen.
Normaly because they feed the cable from the laptop mainboard through or near the hinges of the screen.
It is not always the case that you need a whole new screen at all Gary
As for the WiFi, that also takes the same route, Both the wires are simply connected to a large flat foil alloy sheet that acts as the aerial, found between the lid of the laptop and the back of the Lcd screen unit.
You can buy a new cable for about £35, it depends on the model of acer laptop it is.