iPhone5 how to fix the black screen please help

Please help.

My iPhone 5 had an unfortunate encounter with the concrete. The screen was in one piece but went black although I can still receive calls/texts, turn it off and on, lock unlock, vibrate etc. When viewing the screen under a bright light you can see that the screen itself still works, you can make out the icons open applications, but it's virtually impossible to see.

I have tried resetting it with the home and lock button, syncing it, and after much of a faff with disabling 'Find my iPhone', restoring it. Nothing worked.

I've taken it to a local repair shop they tried to diagnose the problem by testing it with a new screen, but the new screen didn't work either.

Googling it doesn't really give me much more than resetting, testing the connections, or replacing the screen. :(

Any other suggestions?

Thanks with upmost kindness.
Sarah