Lenovo Yoga 3Pro 1370 - Too low voltage at all USB ports

[ra-ma]

Hi, since a couple of days the USB ports at my Yoga 3 Pro don't work anymore. Whatever device I'm connecting - there's no indication of "life" (no light/no connection). This is the case within Windows, but also while powering up (USB boot), it's not working. Besides that everything else works including illuminated keyboard etc. Also there's no error in the Windows device manager.

I measured the voltage and it appears that only 0.3 volts are present at all USB ports.

Luckily I was able to find a schematic (attached). Unfortunately no circuit diagram, but main components are labelled on the board (like "U40").

When measuring on the board I find that at PJ7 "+5VDX_WALKPORT" (page 29 left) only some 0.3 volts are present. All other voltages like 3.3V, 1.8V etc. are present and even 5V at PJ4. At the capacitor PC42 I measure 8V at the connection towards the ISL.

Visually I can't find obvious damages. Does anybody have an idea where to look next?

[amyk]

The last page of the schematic (power distribution diagram) shows TPS62130s for a few of the power rails, but there are no other mentions of TPS62130 elsewhere. Is it a fake schematic?