LCD screen: can this problem be caused by the inverter?
It is the LCD panel.

I bought an external controller model M.NT68676.2 that includes its own inverter and flat cable. I fed it the signal from a RaspberryPi and As you can see from the picture, the screen is corrupted the same way it looked when connected to the computer's motherboard.



And here's a picture of the setup, hope it helps.