Diagnosing iPhone 5s no power Diode Readings

I’m working on an iPhone 5s that randomly stopped powering on or charging. Ive done some resistance testing to look for shorts, but i dont have known good readings to compare.

Diode mode readings:

Vcc main 0.359

Pp5v0_usb 0.000/OL

Pp batt vcc conn 0.401

Pp1v8 0.410

Pp1v2sdram 0.271

Pp5v0 usb prot 0.556

Mic1 to codec p OL

Any ideas to lead me towards a solution? Does the pp5v0usb OL look important, i only see 3 caps next to the connector highlighted on that line in zxw?

Pp5v0 usb conn is ol, but im not sure this is significant. Pp5v0 usb prot was .556. Does anything beginning with pp5v0 lie on the same line? And what is pp5v0 as it relates to the operation of the phone?

The charging MOSFET Q4 had a few solder balls at the base of the underfill.

How would you proceed with testing voltages, especially around the charging circuit and maybe tristar to determine the issue?