had a phone from(h860n 2sim version) 06/2016 after 6-8 months screen ghosting after then gps issuses appeared ghosting annoying but not major for me so give the phone for rma, no problem for 6 months gps after again so i opened google and phone inside what fkn problem i saw dirt ,humidity problem greenish spots in the back case that locations clean them add some aluminum foil there voila no problem for until now, So today,i open the inside phone again, clean the those 3 locations from appeared dirt,moisture green dots again now fixed (open area—15-20 sat locked in 20 sec) i dont know how gonna long this time :) My solution for this clean the 3 locations up ther phone back cover inside when ever gonna fail…(for me 3-6months period) (gps status from window)