When there is no touch on the iPad with a new screen. Most likely the Filters or diodes went out. So make sure to test with a new screen first to make sure that this is a motherboard related issue.
You can send in only the iPad Pro motherboard with this repair. Do no send in full device. The bad Diode or filter is caused by tech error 50% of the time. and the other 50% from a bad screen, water damage or a drop to the device.