Why is my Xbox Elite Series 2 controller not connecting to my pc while plugged in?

I recently disassembled my Xbox Elite Series 2 controller to replace both of my tactile switches, after struggling to take out and replace the switches I put the controller back together and tested it out using gamepadtester.com. I plugged the controller into my pc and the light lit up, but the controller is not responding. Whenever I turn it on, it works for half a second then stops working. I am very upset because I spent hours trying to replace the tactile switches and now my controller will not work. What should I do to fix this? Please help, thank you.