Help everytime i make a call my screen goes black and won't return until phone has ended. Why is that? What can i do? I could not even call T Mobile customer support because i could not access my dialer buttons. Please help!

I am experiencing the same problem. Calling out, screen goes blank.

Need an immediate resolution, otherwise will return within 14 days period going with Samsung Exhibit II.

Really dissapointed with HTC Radar II.

Had the same problem. Found that removing my screen protector allowed the phone to function properly again. Apparently the proximity sensor in the phone that locks the screen when you place it near your ear, views the screen protector as some kind of a surface also. So...  Hope this helps you.

i fixed the problem by cutting the small layer of the protector which covered the proximity sensor, fixed it instantly

Can you share the picture/location where you need to cut?

THank you

I have replaced the screen on my HTC radar. I bought the LCD and digitizer assembly. Since then the proximity sensor won't work. When I make a call the screen goes black. I have found that putting some pressure around that area (top left corner) brings it back but as soon as I let go it stops working again. I did not use new adhesive when putting the screen back and there is some light leakage between the digitizer glass and plastic frame it fits into. I have darkened it out with electrical tape but still no joy. Any ideas. Do you think cutting the small plastic cap that covers the proximity sensor would help?

I had this problem with mine and came across this page.

Solution for me was to press over the proximity sensor really hard with my thumb, and then scrape my thumb across it a few times when in a call.

Worked for me.