Surface Pro 3 wont cut on after Screen replacement

Both the LCD and battery connectors have a tiny PC board that sits between the MB and the connector. When you disconnect the cable, there is nothing holding them in place and they often come loose and get lost. If the LCD one is missing, nothing shows on the screen. But it will turn on. You can check this by connecting a monitor via the HDMI cable. If the battery one is missing, it won’t charge and won’t turn on unless the power cable is plugged in.

I replaced the screen in one unit as well (completely destroying the old one in the progress like everyone does) and installed a new one. When I got the replacement screen it was delivered without the connecting cable to the motherboard (next to the connector for the digitizer and the battery) so I had to use the former one.

When I tried to power it up it would not show any signs of life so I connected an external monitor just to be sure and it worked like a charm. I found that the connection from the lcd to the motherboard was kind of wacky and wobbly so I used a small strip of duct tape under the metal strip which should do the job and it held perfectly.

By the way my unit would run easily without a battery connected!