Chosen Solution

I got a phone from a friend who needed help replacing the screen after dropping it and breaking it. First thing before even buying a new screen I wanted to see if the phone is still working so I plugged it in my computer, itunes installed, but my computer can’t see it at all. (No device recognition sound or anything on the computer screen, itunes can’t see it) How can I fix it?

After charging it for about half hour it showed sign of life. Weird I thought it could power on without a battery.

Press and hold the two buttons at the same time