Lenovo E590

[Jane]

Lenovo E590 is shorted. With a thermocamera I found out hot IC U4305 and D4311 - please see in the picture enclosed - I circled them.
Do you think the culprit is IC U4305? Is it possible to bridge the ic ( from IN to OUT pins to be sure it is the culprit)?
What would you suggest?
Thank you for help

[mon2]

Yes, the fault is most likely this IC. This IC is a USB load switch that is intended to limit the current on VBUS to the slave USB device.

Start with checking the resistance to ground of the VBUS pin on the USB connector that this load switch supports. Is the resistance low? If yes, then the fault can be the external parts on this same VBUS rail.

Flux and remove the USB loadswitch (U4305) and then test the resistance to ground again of the same VBUS rail. If the VBUS resistance is higher, then this load switch needs to be replaced. There are only a few parts around this loadswitch - flux and remove each to confirm the fault is with the IC and not the external parts.

USB load switches do fail often.

[Jane]

I removed the USB loadswitch (U4305) and measured the resistance on VBUS rail like this
Input ( pin 3): 8.3M Ohm
Output ( pin 4): 0,16k Ohm

I guess there must be a short on the rail beyond the pin 4. What do you think?

What voltage and current should I use for testing via thermo camera ?

Thank you for help

[mon2]

Flux and remove the capacitor at c4302. Test the resistance again.