For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
He is a field tech, always plugging his lan into various devices; maybe D4000/1 (ESD protection) are faulty. This is similar to what I find on USB in fact.
I'll measure / swap them quick and report back.