What causes dead zones on digitizer?
I also had this issue recently. I only had one, vertical band, but it still affected use, mostly typing. I demonstrated the issue (seen below) and contacted the [ebay] seller. They promptly classified it as defective and sent me a new one. This will most likely be the solution to your problem as well. As I did, I would use a drawing program to verify, and inquire about a replacement screen and digitizer.