Touch ID and screen issues - Help needed

[Khizer Hayat2]

I recently purchased a used iPhone 6 64GB but have certain problems.
1. It feels that LCD screen has been changed, how can I know if it is changed?

2. When I force restart iPhone by pressing home and power button simultaneously, screen turns green for a bit. What it could be?

3. I am on iOS 10.1.1 and when I set up my Touch ID it works fine but after sometime it do not recognise my finger.

All suggestions and recommendations will be highly appreciated

 

[anon(9602380)]

1. You will need to remove the screen and looks for things on the back that will give it away. Like missing  logo's, rough edges, cables being the same thickness and so on.

2. Normal. My 6 and 7 Plus both do it.

3. Not much to suggest here. If the screen was replaced, then it possibly may not have been put back together properly. Try deleting your Touch ID fingerprints and redoing them. If that does not work, might be a good idea to factory restore your phone to new and starting over. If either suggestion does not work, may be time to have it looked at by an  Genuis.

 

[Khizer Hayat2]

3. Not much to suggest here. If the screen was replaced, then it possibly may not have been put back together properly. Try deleting your Touch ID fingerprints and redoing them. If that does not work, might be a good idea to factory restore your phone to new and starting over. If either suggestion does not work, may be time to have it looked at by an  Genuis.

Thank you for your reply. I can add whatever finger I want and it does work for a while but stop working soon. I hope checking screen and then placing it in a right position my solve the problem.