DELL XPS 13 7390 no power, short 5alw & 3alw

[pc_okay]

Hello guys,

I have this board, taking no voltage on usb-c.
After some diging, i found that 5alw (1ohm to ground) & 3alw (7ohms to ground) are both short to ground
So i open jumps @PJP300 & @PJP401 and found no shortage on both 5alwP & 3alwp.

So i try to inject on both 3alw & 5alw with no luck: i get some heat on UC22 & UC23 but that's all.

And now i'm stuck.

Please find attach schematics. Link to schematic --> https://www.badcaps.net/forum/troubl...15#post1661615

Any ideas?

Thanks !

[mon2]

With no power to the board, what is the resistance to ground of:

+3VALW
+5VALW

NB: Best to copy & paste the full net names from the schematic so they are easier to follow in the review.

[pc_okay]

+3VALW 1 ohm
+5VALW 7ohms

thanks

[mon2]

These are very low resistance measurements. For your injection, keep the voltage @ 1v but increase the current to 3A-5A range. Inject again to check who heats up.

[pc_okay]

Hello,

UC22 heat @ 70°C~ taking 1.5 amp max.

Thanks.

[pc_okay]

Hello,

I'm still stuck with this board, i remove the UC22 but still get low resistance, i inject again and another chip heat : UPD2.
I remove it but still get low res !


When i remove UPD1 i get a correct resistance to ground on +3VALW only.

Any idea?