, looking at this diagram i see all components except the 2 zenerdiodes (closest to the port).
or sony did removed them (it's actually one part with 2 zenerdiodes in it), or it is located under the port. (if thats possible in the first place)
now what components can short, in my opinion only that unseen part or the control ic (8 pins)
btw that ic also tells the cpu that there is over current on one of the usb ports, and normally the cpu will cut down the power to that port, but on boot up it may not be ready to do that.
about the TH3301, you could try to cut the trace instead of desoldering.
keep us informed