Receiving PPF004/003 after replacing Left Fan (Twice)

Hey iFixIt Team,

Trying to get second opinions on a diagnosis.

Went ahead and replaced both fans during a procedure to prevent a noisy left fan (orientated as if you were using), After I had replaced both fans I noticed that my left fan would run a full speed and could not be controlled via fan tools (Ex. SmcFanControl). The right fan in this case would work as intended.

From research, it looks like it could be an issue of either the fan, an associated cable (Potentially keyboard)/or a cable seat. I feel confident in ruling out the physical fans, the cable seating looks as expected, and I'm still able to use the keyboard (and all other aspects of the computer) without issue.

Question is: Is there a way (other than visual inspection) to validate that a cable is broken? Could the issue potentially be something with the logic board?

If anyone has experienced something similar I'd be interested to hear what eventually solved it as I'd like to avoid throwing parts at it without a confident diagnosis in place.

Thanks, everyone!