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.
Yes L7310 was also pulsing, but when inspecting U6100 I could see that the SPI_C50_L trace looked bad. The connection on this line was broken right at the measuring point.
Just barely managed to jump wire to the tiny residue of the measuring point. Fan started spinning after the line was fixed. So thank you for getting me on the right track.