820-01700-A 5V 297mA

[mbcontrol]

I need help with a 820-01700-A. It came with liquid damage and one completely dead usb-c port. Three usb-c ports was working with 20v and booting into the login mask. I fixed the liquid damage areas on the board. The most liquid damage was around UB300, UB400, UB700, QB701, LB700, R8601, C9081 and U5800.

After changing the UB400 (CD3217B12) for the dead usb-c port, all four ports are stacking now at 5v and ca. 297mA.
Because UB300 was also liquid damaged, i changed it renewed it also - so UB300 and UB400 are new.

I bought the "new" CD3217B12 chips from CN/Ali. They look like really new - not reballed. I hope they didn't sell me fake-chips. I Didn't see chips like this before - normaly they look reballed and used.

Here are my measurements (sorry for the long list):

PPBUS_G3H = 12,29V
PPBUS_HS_GPU = 12,29V
PPBUS_HS_GPU = 12,29V
PPBUS_HS_OTH5V = 12,29V
PPBUS_HS_3V3G3H_T = 12,29V
PPBUS_HS_3V3G3HRTC_X = 12,29V
PP5V_G3S = 12,29V

PP3V3_G3H_RTC_X = 3,36V
PP1V8_SLPS2R = 1,80V
TBT_WAKE_L = 1,79V
TBT_WAKE_3V3_L = 3,31V

PPDCIN_G3H = 5,10V
PPDCIN_XA_G3H_F = 5,10V
PPDCIN_XB_G3H_F = 5,10V

PCH_RTC_RESET_L = 3,00V
PP3V3_G3H_T = 3,30V
PMU_ONOFF_L = 3,30V

PPVBUS_USBC_XB = 5,11V
PPVBUS_USBC_XA = 5,11V

PP3V3_UPC_TA_LDO = 3,35V
PP3V3_UPC_TB_LDO = 3,35V
PP3V3_UPC_XA_LDO = 3,38V
PP3V3_UPC_XB_LDO = 3,38V

PP1V5_UPC_XA_LDO_CORE = 1,58V
PP1V5_UPC_XB_LDO_CORE = 1,58V
PP1V5_UPC_TA_LDO_CORE = 1,58V
PP1V5_UPC_TB_LDO_CORE = 1,59V

Here comes the rails without voltage:
PPVCC_S0_CPU = 0V / 2,92Ohm
PP1V8_G3S = 0V / ca. 205Ohm
PP1V8_S5 = 0V

L9520 Pin2 (PP0V9_SSD0) = 0V (Diod = 0,34V
L9530 Pin2 (PP1V8_SSD0) = 0V (Diod = 0,35V
L9020 Pin2 (PP0V9_SSD1) = 0V (Diod = 0,14V, after a while second measurement 0,43V)
L9030 Pin2 (PP1V8_SSD1) = 0V (Diod = 0,25V, after a while second measurement 0,40V)
L9080 Pin2 (PP2V5_NAND_SSD1) = 0V (Diod = 0,08V, after a while second measurement 0,41V)

Enter in DFU-Mode is possible.

 

[2informaticos]

"Enter in DFU-Mode is possible."
Can you do revive?
T2 requires SSD voltages; compare diode mode readings for the power rails between both channels SSD0/1.
Not good to get liquid sign around SSD power supply...

 

[mbcontrol]

DFU-Mode revive: It runs over the 4 steps and then it takes a minute or two showing this error message ...
"Gave up waiting for device to transition from DFU state to DFU state. com.apple.MobileDevice.MobileRestore - 0xFA (4005)"

Diode-Mode measurements:
PP1V8_SSD0 = 0,35V
PP0V9_SSD0 = 0,36V
PP2V5_NAND_SSD0 = 0,39V
SSD0_S4E0_VPP = 0,56V

PP1V8_SSD1 = 0,41V
PP0V9_SSD1 = 0,46V
PP2V5_NAND_SSD1 = 0,43V
SSD1_S4E0_VPP = 0,56V

Measuring this rails i found out something:
The first measurement (Diode-Mode) showed me ...
PP3V3_G3H_SSD1_SNS = 0,37V
PP3V3_G3H_SSD0_SNS = 0,39V

Shortly after connecting and disconnecting the charger, the measurement shows me ...
PP3V3_G3H_SSD1_SNS = -0,49V
PP3V3_G3H_SSD0_SNS = 0,05V

PP3V3_G3H_SSD1_SNS climbs up to 0,37V while measuring in 2-3 seconds.
PP3V3_G3H_SSD0_SNS stays for minutes at 0,05V and climbs up slowly to 0,39V.

What do you think - could this be the issue? What can i do next?

 

[2informaticos]

Allow 10-15s to discharge remanent voltage, before checking diode mode, or resistance on the board.

Doesn't seem to have short, nor low resistance on SSD power rails.
However, there is a problem.
T2 cannot complete DFU, because couldn't get access to its dedicated firmware partition on SSD.
If you check the power sequence from a T2 platform board, you can see the SSD voltages MUST appear before S5 state, immediately after G3S.

Something happened when you've changed UB300/400; the heat affected SSD0 area.
SSD was working before, as you've got into login screen.
Check for knocked off components, or broken traces.