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

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!

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.

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?

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.

I replaced both USBC_XA diodes, and now the readings are normal, like the rest; however, the issue persists.
Yes, I did all tests with red on ground per "Rossmann Repair Training Guide - page 78"
U3100 LDO 0.514
U3200 LDO 0.500

You should replace the CD3217 chip.
Bad diodes means overvoltage occured; the chip may be affected.
Be aware, you need the chip from donor board, same position!