Moto x2 screen strange behaviour (green led + more)

Hi, I have a moto x 2nd gen phone. I seek for an expert's ideas on what the cause for my phone's behaviour is. Any help much appreciated. My phone: Can get into safe mode, lets me choose recovery/normal startup options but once I choose them the screen goes off. If chosen "Normal startup" the phone boots with the screen off. Sometimes before seeing the moto logo a green LED light turn on for a bit, then the logo, vibrating sound as it boots, then screen goes OFF. How do I know it's booting? Well, if I wait a minute or so, I can tap the power button, tap it again, and I will hear the closing screen sound. I can tap it once then attempt to take a screenshot and the sound of taking a screenshot can be heard. At some point my 11 oclock alarm suddenly started ringing, with the screen OFF. What does this mean, in combination with the green LED? Why does the screen work fine when in safe mode? Why did this happen after I replaced the screen & touch? I hope this info will help you reach a conclusion, I kindly ask for your help as posting my question is my last hope. Thank you.