Ipad Mini: half screen unresponsive?

Model A1454

A friend gave me an older model Ipad Mini that had a bad digitizer. I couldn't tell if half of the touchscreen was bad because the digitizer was damage. After replacing it the left half of the screen is unresponsive. I've tried updating the system to the latest software and resetting to factory mode. I've checked all connections but they all looks good. Is the touchscreen bad? How can I determine if the touchscreen is bad? Even with rotating the ipad only half of the screen is working; no other problem/issue/error, just half of the touchscreen unresponsive. Ideas?