Most of the first batch of Samsung Galaxy S7 suffers from infamous pink line issue. A one or series of vertical pink line just develops a course of time. This mostly affects first batch of galaxy S7 edge. The reason for the pink line is the problem with flex cable that attaches to the screen. The cause for this issue is Samsung Galaxy S7 edge suffers from overheating issue. When used constant for long over time or playing high end games causes the device to heat up and melts the glue that attaches the ribbon.
If you suffer from this issue you can try the following solutions which may fix your device temporary or permanently depending on the method used. Use the method on your own risk.
1 Press near the camera region with the help of fingers for 2-5 sec.
2 On phone dialer press *#0*# test red blue green colour 5-10 times
3 If you are still under warranty get your lcd replaced under free of cost.
4 If none of the method works try the method provided on the XDA threads
I hope this method listed will help your Samsung galaxy edge recover from this pink line issue.