OK i have had same issue as all other . and seems like matey frome earlier post is correct . some supplies are selling the gt version and the plane i380 as working on both well it bloody don't !! I sourced one specific for the gt and it work straight of . and still the supplier insists 100% it defiantly works with both. so sorry to say you will have to buy the correct one i did find mine on ebay for a 10 pound. also you can see physical deferences
1. ribbon is too long and no way to make the lines line up.
2. down near the home button the vertical lines are longer on the gt version ( on back )
3. on the back top there is gnd and x9 symbols below the earpieace hole on left as you looking at it from back on plain version i.e not gt . there few more deferences but they main ones . i hope this helps . good luck !!