820-02016 dont turn on

[Dozer]

hi got this device with liquid damage.

first accu was not good, with other one it turned on but dont recogniced the charger

after that i found liquid damage around U5200 and around F5200

i cleaned that up, found i2c_smc_pwr_3V3_scl had to high value in diode mode, replaced UD201, then scl and sda had same good value in diode mode

after that it dont turn on anymore :-(

found broken trace from R5221 to C5220, after repair resistance on C5220 is about 3 ohm and diode mode is ok pad 1 and 2
C5260 same, 3ohm diode mode is ok


still dont turn on 5V 0A, no DFU mode


the area around UF400/401 looks super good

FF200/201 is both pads 5V

but: CF408 pad 1 ( PP3V3_UPC0_LD0) is only 3.3V when pluged usb-c cable in the corospondending port

in one port plugged in PP3V3_UPC0_LD0 is 3V and CF508 Pad 1 PP3V3_UPC1_LD0 is 0.1V
pluged in the other port then in one port plugged in PP3V3_UPC0_LD0 is 0,1V and CF508 Pad 1 PP3V3_UPC1_LD0 is 3.3V

tested on a good board there are no matter where pluged in all time both PP3V3_UPC0_LD0 and PP3V3_UPC1_LD0 is 3.3V

checked around UF260 looks clean, did reflow to be shure, in diodemode all pads measurements are like on the good board

i have no idea what else to check. the dc in cable i checked with the good board that is ok.

need help please or an idea

 

[2informaticos]

You should compare diode mode readings to ground between both boards; on the USB-C area.

Did you test if now the board turns on with good battery (holding some charge)?

 

[Dozer]

cant find any difference in the usb-c area, checked in diode mode and with mac usbc&edp meter

checked with known good battery and out of the case and in the case, stucks on 5V all the time

i replaced UF260 with the good working board but still the same, the good working board works with this TBT Rom and the bad board no signs of change with the TBT Rom from the good board.

perhaps they (the 2 USBC controller UF 000/100 ) dont comunicate with each other? the spi lines in diode mode are ok, perhaps should i try to replace the 2 controllers? but if CF408 pad 1 ( PP3V3_UPC0_LD0) is 3.3V by conecting the power cable to the corespondending port it looks for me that the controller should work?

 

[2informaticos]

Something else has been affected by liquid.
Geting LDO doesn't mean the communication is good for the controller.
Corrosion may affect data lines.