Lenavo Yoga 720: No power from USB-C port

[keerthi123]

I am trying to fix Lenavo Yoga 720 and no power is coming from USB-C. Seems TPS6598 (see attached image) is communicating with USB-C port.
according to the attached image:
What is 1175J?
Also two other 4 pin ICs nearby 1175J?
Also for testing can I cheat by providing external signal to TPS6598 get the power rails activated?

[keerthi123]

So no power at nearby fuse (visible in the image) . Is battery charge controller IC (BQ25700) also communicating with the USB-C charger?

[winniethepooh_icu]

You have one of two possibilities with the TPS65982:
1) The internal power switch is controlling the 5V power.
2) It is driving external NMOS via HV_GATE1 and HV_GATE2 pins.

I can not see in your picture whether there are traces leaving HV_GATE2 on the top layer (it is on the edge of the IC so this is possible).  If so, you can follow this trace to the power switch.  If a trace leaves SENSN you can follow it to the sense resistor which will allow you to find the power path.  If there is an external power switch, you should watch the gate when you connect a device, the gate should be driven somewhere between 4.5V and 7.5V only when a device is attached.  The power switch (whether internal or external) will not activate until attach is detected on the CC pins.

The ESD protection level of the TPS65982 is rather poor and it would be assumed that there is external protection for the CC pins; It would be worth checking to see if the CC pins are behaving normally - See USB Type C specification from USBIF.org for an explanation of how these pins work.

[keerthi123]

I found that there is  crack on BQ25700 and going to replace it frist.