820-01814A (A1990) 5V @ .225A

ViBe

New member
I've been lurking long enough and need to get into the mix. Thanks for all of the advice before this thread, because it got me here today.

Customer brought in an A1990 with board 820-01814A. It's stuck at 5V pulling .225A. All 4 USB-C ports have been tested; only 3 were functional.

I'm using the schematic for a 820-01041. No spill damage*; this is a super clean board.

Off the bat, UB300 was visibly fried, and components CB3902, RB258, CB313, CB314, CB301, & R4808 all appeared bad or burned with a small amount of what looked like corrosion.* All of those components were removed. RB258 & R4808 were replaced with new resistors.

Many 3V3 rails are present, but no 5V rails. I thought this was beginning to sound like a T2 firmware issue, so I started down that road as well. Using Apple Configurator 2, I've tried the Actions -> Advanced -> Revive Device option several times with the target machine successfully in DFU mode. No joy...

PPBUS_G3H: 12.3V
PPVBAT_G3H_CHGR_REG: 12.3V
PP3V3_G3H: 3.399V
PP3V3_UPC_XA_LDO: 3.366V
PP3V3_UPC_XB_LDO: 3.375V
PP3V3_TBT_X_SX: 1.668V
PP3V3_G3H_RTC_X: 3.398V
PP3V3_G3H_SOCPMU: 3.324V
PP3V3_AWAKE: 3.323V
PP3V0_G3H_RTC: 3.007V
PMU_ONOFF_L: 3.373V
PMU_ACTIVE_READY: 1.8V
PMU_LDO2_OUT: 1.8V
PMU_VDD_MAX: 3.368V
PP1V1_SLPS2R: 1.104V
PP1V8_SLPS2R_PMUVDDGPIO 1.806
PP20V_USBC_XA_VBUS: 5.17V
PP20V_USBC_XB_VBUS: 5.14V
PP20V_USBC: 5.17V

Missing:
PP3V3_S0SW_TBT_X_SNS (Diode Mode: .605V) (Ohms to GND: 27.82k)
PP3V3_S5 (Diode Mode: .328V) (Ohms to GND: 10.45k)
PMU_PVDDMAIN_EN (Diode Mode: .767V) (Ohms to GND: 47.2k)
PP5V_S5_LDO (Diode Mode: .490V) (Ohms to GND: 21.k)
P5VG3S_EN (Diode Mode: .592V) (Ohms to GND: 46.4k)
PP5V_S4_X_USBC (Diode Mode: .502V) (Ohms to GND: 16.44k)
PP5V_S4_T_USBC (Diode Mode: .504V) (Ohms to GND: 16.64k)
P5V_3V3G3H_EN (Diode Mode: .596V) (Ohms to GND: 50.4k)
PM_SLP_S4_L (Diode Mode: .808V) (Ohms to GND: 88.5k)
PM_SLP_S5_L (Diode Mode: .806V) (Ohms to GND: 86.7k)
 

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

"No spill damage*; this is a super clean board
----------------------
a small amount of what looked like corrosion"
Corrosion is result of liquid; corroded board cannot be clean, nor super clean...

PPBUS_G3H is incorrect.
SMC doesn't communicate properly with U7000, nor with CD3215 chips.
Read more threads about DFU restore (on the forum).
Some people complained that succeded after many tries and different configurations tested.

All 4 USB-C ports have the same behaviour now?
 

ViBe

New member
Thanks, 2info. 3 of 4 USB-C ports still draw .225A @ 5V. The 4th port doesn't have a replacement CD3215 yet. I'll continue with the DFU procedure, but I'm sticking with the Revive option to prevent data loss associated with the Restore process, as it now wipes out OS and user data. More to follow...
 

ViBe

New member
I found a reference in the Rossmann Store which states "If a SINGLE CD3215 on the board is defective, NONE OF THE OTHERS WILL WORK!" So, this might be my problem. Parts ordered. Will update when the new IC is installed.
 
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