820-00928 Two USB ports don't work. 5V only.

[bjf]

The other two work and go to 20V and current comes through normally. The two near the spill stay at 5V and cycle on and off completely ever second or so. At first, the top one worked and then when I plugged in the bottom one, it showed 5V and then the top one stopped working and started doing the same thing - 5V, on and off cycling. Any ideas? I don't have a board view or schematic so it's hard to describe what got hit. It was pretty minor. Not sure what could be causing this on just one side.

 

[2informaticos]

Not exact boardview/schematic for this board, but still good enough to work with; search the Internet.

Compare diode mode readings between all USB-C ports; check all CD3215's power rails.

Reflow the affected area, or better reball corresponding chips; may need to change them.
Board is fully working on the other 2 ports?

 

[bjf]

The diode readings for the CD3215's compared to a good board are the same. They might still be damaged but they weren't hit directly by the spill. The spill was very minor, just right above UB300 and UB400. I attached a picture of it.

The computer does work fully with the other two USB ports. I installed it in a good top case and everything, including charging and running on battery, worked fine.

What I noticed is that the 5V and off cycle feels basically identical to the 5V and off cycling that happens when you have the battery cable to J6951 but the battery screw not installed and the computer won't turn on. I'm wondering if that might be relevant. I'm also wondering which components or circuits these two ports go through where they would both fail in the same way. It seems like there's a gateway on that side that is failing.

 

[2informaticos]

The CD3215 chips work in pairs.
If one is bad, the other one is affected too.

A battery issue should be present on all 4 ports.
I don't think to be the case.