So the 2 little black things on a vertical trace on the left ? Do they read low resistance like a fuse or inductor ? I don't think I've ever seen diodes in that form, I think just passives get that form with the big metal end caps.
Probably fuse or fusable resistor/ small NTC they thing, or inductors, would be my guess from digital boards and their power rails.
Looks like some Vin filtering going to the Vin of the lt8631, the other side with the blocking cap could be sensing that rail's AC, or where's that trace above (between R2 C5) the cap going to ?