Default [Q]

I'm new to cellphones. I bought a used EVO 4G, rooted it and installed Cyanogen - once. In the process I've done quite a few different commands, but, don't have much memory of them and what they all do.

After a while my screen cracked. First I tried simply replacing the digitizer and when that didn't fix it I got a digitizer/lcd screen assembly. It still didn't work and the problem was the connectors on the main board for the screen, digitizer were bad. I then got a new main board and am getting farther, but, have a new issue.

The first couple of times when I started the phone I wasn't watching but I heard it making sounds and so forth but after a while it just went black. I did a hard reset (clear and then reboot). After that I again tried turning it on (without watching the whole time) and it acted the same. Then I watched the who process and found that it would get as far as the grey background with "4G" in yellow and white letters. After a while the screen would go to sleep but I can't pull the bar down to unlock the screen.

I know there are lots of commands and things I can do with adb, but, it doesn't appear to to be enabled. When I run "adb devices" on my computer while the phone has the grey background and the white and yellow "4G" it doesn't list anything. Then again it seems if the digitizer isn't working there should be an error when booting.

I see there is a bootusb option but I don't remember what it does. Does anyone have any suggestions?