Hi there !
I've found some time to examine (on the top side) another regulator section.
It is pretty close to the regulator 1 section as it is based on the TPS64203 Step down controller, a close friend of the TPS64201 !!
Here is a close up of the regulator components :
Here is the components identification for schematic :
I currently have a draft of this schematic, but the command circuit of the TPS64203's Enable input is getting deep into the board so it's harder to identify the schematic on this !
Here is the schematic of that section. I've made it with Word to have it quickly !
The Enable input is not complete, but it is linked with the rest of the board's design.
That's it for today !