clusterfsck
New member
I've got an 820-00850 logic board that suffered water damage. Board cleaned up well, may have a little corrosion around U9080. The board draws 5V 280mA when connected to a charger alone, 20V 0mA when the battery is connected. Behavior is the same on all 4 USB-C ports. I measured all the usual suspects and nothing seems off.
PP3V3_G3H 3.34V
PPBUS_G3H 12.31V
PP20V_USBC_XB_VBUS 5.24V
PMU_ONOFF_L 3.40V
PP0V8_SLPS2R 0.8V
PP1V1_SLPS2R 1.1V
PP1V8_SLPS2R 1.8V
I was really hoping it was a T2 firmware issue. I can get the board into DFU mode, but it's seen as a generic "Apple Controller" in Apple Configurator 2.6 on a Mac mini. The mini complains "Cannot use thunderbolt accessory" when first connected. Could it be a cable issue?
Symptoms seem similar to this thread https://boards.rossmanngroup.com/threads/59438/. I checked all CD3215 LDO outputs in diode mode and got readings ranging 0.43V-0.48V. Replacing the CD3215s seems to issue in that instance. Is there anything else I should check/try first?
PP3V3_G3H 3.34V
PPBUS_G3H 12.31V
PP20V_USBC_XB_VBUS 5.24V
PMU_ONOFF_L 3.40V
PP0V8_SLPS2R 0.8V
PP1V1_SLPS2R 1.1V
PP1V8_SLPS2R 1.8V
I was really hoping it was a T2 firmware issue. I can get the board into DFU mode, but it's seen as a generic "Apple Controller" in Apple Configurator 2.6 on a Mac mini. The mini complains "Cannot use thunderbolt accessory" when first connected. Could it be a cable issue?
Symptoms seem similar to this thread https://boards.rossmanngroup.com/threads/59438/. I checked all CD3215 LDO outputs in diode mode and got readings ranging 0.43V-0.48V. Replacing the CD3215s seems to issue in that instance. Is there anything else I should check/try first?