Thread: Replacement Screen - Only White displaying

I have a 4NSF Navigon which is known as Skoda Maps and Fun. My vehicle is December 2013 build. When I bought the vehicle the Navigon had deep scratches to the screen. I disassembled to investigate replacement . As part of this ( i must have assembled and disassembled 10 times) the touch screen stopped functioning therefore I researched and ordered a replacement from China. I have bought a replacement device, which means I can repair this one at my leisure either to sell on or to have a spare.
The replacement screen arrived yesterday ano I expected that it would be a simple swap over. With the original screen fitted the device boots to a screen offering options which can be selected, but the touch screen does not allow any further progress. When I swap over the screens ,the new screen illuminates white and no more. Does anyone have any suggestions to troubleshoot? I have tried swapping back and the device is still booting ok, though the cable seems to be damaged and only works intermittently.