Chosen Solution

What is this cord called?

LVDS display cable it connects from the back of the display to the logic board. Review this guide Step 7 for the logic board side iMac Intel 27" EMC 2429 Display Replacement It looks like you snapped the connector tang from the image. This may need more than the cable as you may have also damaged the logic board connector as well. LVDS Cable Apple P/N 922-9848 getting hard to find Often I need to replace the logic board connector when I see this level of damage 30 Pin LVDS Connector for iMac A1311 & A1312 (EARLY 2008 - MID 2011)