Prestigio PMP7170B3G DUO Technical & Service Manual page 21

Troubleshooting 6 : Capacitive touch screen problems
1,check if Capacitive touch screen FPC (J1502) connect fix well.
2.Check if VGP2 VCC is 3.3V(VR1506) . if not, check U00301.
3.Check if SCL0 VCC is 1.8V .
4.Check if Sda0 VCC is 1.8V .
5.Check if touch panel is damage.