For months I’ve been dealing with an issue of the screen going black when I answer or make a phone call on my HTC HD7. I searched online and wasn’t able to find a solution until today.
It has to do with the proximity sensor. It goes out of alignment and that results in the black screen during the call. While the call is active, since the screen is essentially turned off by the proximity sensor, I can’t use the keypad or even hang up the call!
The fix is to press down hard on the area where the proximity sensor is. It’s located at the top of the screen – pretty much where the HTC logo is. Just press hard on that area and that should move the sensor back into place.