Screen is auto dimming and very dark
Here is the problem:
If I leave the phone for a couple of minutes with locked screen and then unlock it the screen brightness is normal but if I do something on it the after 2-3 minutes the screen goes very dark. Also the auto brightness is not working. What can be the problem? Maybe temperature sensor or proximity?
Update (05/14/2016)
The CPU is getting extremely hot and the screen starts dimming. When I try to put my thumb on the CPU to get it cooler the screen is getting back with normal light. Any help about what can cause CPU overheating?
Is this a good question?