Hi @theacook ,
The video cable may be damaged where it passes through the hinge area between the body of the laptop and the lid.
Here’s a link to the [https://thinkpads.com/support/hmm/hmm_pdf/43y6629_05.pdf|service manual] for the laptop.
Scroll to p.116 to view the necessary pre-requisite steps and then the procedure to remove the display assembly.
This will allow you to inspect the video cable for any damage and also its’ connections to the motherboard and the display panel in case one is loose etc.