Dropped phone-blank screen

I dropped my phone, the back came off, but battery didn’t fall out! Went to answer the call and screen was black! Removed battery to turn off. held power key to turn back on, phone vibrated, but black screen. Removed battery to shut off. I have tried all of the suggestions,plugged in to see if fully charged and phone vibrated to signal charging, left plugged in for 2 hours. Unplugged took out battery. Tried soft reset,phone vibrated after about 30 seconds. Black screen. Took out battery. Tried booting in safe mode. Phone vibrated. Black screen.Couldn’t see how far it got on screen with device name. Took out battery. Tried Wiping cache partition and factory reset. Phone again vibrated. Black screen. I have a program on my CPU that I can mirror my phone, via USB cable. Using mouse and keyboard on the phone screen. Plugged phone in USB, turned phone on, phone vibrated, started program and couldn’t find device. Black screen. Now while phone is plugged in through USB and charging plug-in, phone vibrates about every 15 to 20 seconds, fairly long buzz. BLACK SCREEN. LOL!! Please help!!