You are buying a IR remote control sensor board from a C1 77" LG OLED TV. 

I have owned this TV since new. Everything with the TV worked 100% up till the bottom edge of the screen got damaged.

This sensor board does fit or interchange with other models, but that should be verified by LG for your model. Or have your old board out to do a visual confirmation to verify it is the SAME before making a purchase. 

DO NOT buy this if you are not sure if this is your problem or if you are not sure if this is correct for you model!