820-01700-A, 1st (top left) usb-c port is dead

[djab203]

820-01700-A has no issues other than the 1st (top left) USB-C port is dead. The other 3 ports work fine. I've checked the entire board, and there is no liquid damage. All ports are clean. I've tried a new port, and still, nothing shows on the ampmeter. Please help!

 

[2informaticos]

First of all, welcome to the forum!

Check diode mode to ground on CC1/2 lines corresponding to that port.
Compare readings with any other port.

 

[djab203]

Hi. Thank you. Here are my readings

USBC_XA_CC1 = 2.390 (U3100)
USBC_XA_CC2 = 2.391
USBC_XB_CC1 = 0.585 (U3200)
USBC_XB_CC2 = 0.583

USBC_TA_CC1 = 0.585 (UB300)
USBC_TA_CC2 = 0.585
USBC_TB_CC1 = 0.585 (UB400)
USBC_TB_CC2 = 0.585

Compared to the others, USBC_XA readings are different. Bad diode or U3100?

 

[2informaticos]

Bad diode can cause higher values.
Did you check all with red probe on ground for sure?

Check diode mode on LDO lines of U3100; compare with other ports.