m15 R4, broken LCD, won't turn on

Hey all, I have a m15 R4. Had my laptop at work and left it connected to an HDMI cable. When I stood up and tried to walk away the HDMI cable didn't unplug and it pulled the laptop out of my hands and smashy smashy, it killed my LCD screen. I took it to a local repair place and they removed the LCD screen for me but they couldn't get DELL parts. So until I send it back into DELL for repair, I've been trying to use the base/keyboard/trackpad with an external monitor plugged into HDMI. But it just beeps at me when I try and turn it on. According to the interwebs, that means it's not detecting the display. Is there anyway to trick the hardware into turning on with an external display plugged in?