820-00840 (missing 20v) water damage

[KC Micro Tronix]

This one has me stumped.
PP3V42 is good and was measured at the CD3215's
The CD3215's appear operational and light up on thermal normally.
None of the rails appear shorted. (but we are not getting 20v at this point)

There was water damage on this board. Most all the damage was localized round U2890 I had to replace all the pull up 3.3K resistors that were tied to 3V3 TBT X Flash as well as the cap. I also pulled and inspected U2890 for pad damage and reflowed.

I am not getting 20v on the charger. I see some chitchat activity and can watch each CD3215 light up on thermal when I move from jack to jack. Current draw is almost 0. I have diode checked all around the TI CD3215 chips and compared against my reference board. Everything passes in diode test. I do not think there is a issue with either of the CD3215's and water was not present in this area.

I have read the data sheet on U2890 and don't see how a serial data storage device could be the cause of this.
I need to learn more about the CD3215's

If anyone has any input I would greatly appreciate it.

 

[2informaticos]

U2890 is like a USB-C BIOS for U2800, which also connects with CD3215 chips.
Once I found damaged pads and even lost one trace inside board to U2800; board was never recovered.

Check with o-scope if you get any activity on its MISO/MOSI pins.

Keep in mind, it is very close to backlight filter caps.
An overvoltage (because of liquid) could damaged U2800.

 

[KC Micro Tronix]

I went ahead and replaced U2800 and it did not change anything.
Looking around the area closer I discovered what could possibly damaged pads under a chip just to the north and east of U2800. I pulled it and found three damaged pads. One I am not sure where it goes. My schematic does not show this chip.

If you had a board view with this chip it would be helpful.
board shows up as 820-00840-01 but this chip is also present on my -A boards.
I have one pad that is in question.

 

[KC Micro Tronix]

I was able to get a micro drop of solder on the nub anc curled a jumper I green'ed in place. Wish me luck because I have no idea where this pad goes.

 

[KC Micro Tronix]

After this repair I gave up. This board is not getting fixed.
I will harvest it's processor to save a different board.

 

[2informaticos]

That is USB redriver, already posted Aliexpress link to buy it.
The problem is no schematic shows this chip...
I had a board working without that chip, but no USB device recognized...

 

[KC Micro Tronix]

I appreciate that input. It basically tells me that was a rabbit hole anyway. I decided enough was enough