820-01041 5v 50mA no visible corrosion

[Outofwhack]

ppbus_g3h 12.3v

(
I noticed that if I have battery connected charger does switch to 20v but zero current flows.
Another board I have only boots with battery connected otherwise the charger sits at 5volts.
So should these boards be debugged with battery connected to allow charger to get to 20v?
)

 

[2informaticos]

Not really true.
However never can trust Apple stuff.
Is better to have known good battery.

I repaired one few days ago; switched to 20V without battery connected.
In fact, it was stuck in 5V, until I disconnected the battery and machine came back to life; with charger alone.
After tested working good, I reconnected the battery and charged correctly.

 

[Outofwhack]

Thanks for clearing that up.
Could I get some guidance on finding the problem with the board. I have a new battery for it so should be able to rule the battery out.

 

[2informaticos]

Did you try DFU?

 

[Outofwhack]

Im trying DFU and I see 'DFU' on host Mac [even without jumping swk003] but when I click update I get message "Configurator could not perform the requested action. Apple Controller devices do not support this action"

 

[2informaticos]

Did you try both Revive and Restore options?
Be aware, Restore will erase SSD, if succeed.

 

[Outofwhack]

Ive tried both revive and restore and both timeout with message "The system cannot be restored on this device. Gave up waiting for device to transition from DFU state to DFU state.com.apple.MobileDevice.MobileRestore - 0xFA5 (4005)
Pardon my use of phone to snap screen image
I have the board out of the case with nothing attached and finding I get the large DFU icon on the host without having to short the pads to get the board into DFU mode.

 

[Outofwhack]

DFU would not work as displayed above.
As a recap the board is stuck at 5volts, 3 USB ports draw around 50mA and one draws zero.
The one drawing zero is the top left (XB) when sat at laptop.
Out of interest when I put an oscilloscope on the clock signal of the flash memory I can see the burst of clock signal when I power the 3 CD3215s that draw current.
No burst of clock signal on the CD3215 drawing zero (XB).
Both signals USBC_X_RESET_L and USBC_T_RESET_L are 0v when powered on X side and T side and there are no pull up resistors to find.

I tried to follow the steps in logic.wiki for CD3215 boot up sequence.

		PP3V3_UPC_XB_LDO	3.2v
		PP1V8_UPC_XB_LDOA	1.8v
		PP1V8_UPC_XB_LDOD	1.8v
		PP1V1_UPC_XB_LDO_BMC	0v (0.44v diode mode)
		HV_GATE1	0.36v (10.9v seen on other ports when powered)
		HV_GATE2	4.5v (6.7v seen on other ports when powered)
		PPDCIN_G3H	0v (5.2v seen on other ports when powered)

 

[2informaticos]

1V1 LDO can only appear on the powered port.
Compare diode mode to ground on LDO lines of bad port with another port.

 

[Outofwhack]

CD3215 XB = U3200
CD3215 XA = U3100
CD3215 TA = UB300
CD3215 TA = UB400

	Voltage (when relevant port powered)	Diode Mode
PP3V3_UPC_XB_LDO	3.2	0.42
PP1V8_UPC_XB_LDOA	1.8	0.477
PP1V8_UPC_XB_LDOD	1.8	0.443
PP1V1_UPC_XB_LDO_BMC	0v	0.443
PP3V3_UPC_XA_LDO	3.3	0.465
PP1V8_UPC_XA_LDOA	1.8	0.478
PP1V8_UPC_XA_LDOD	1.8	0.43
PP1V1_UPC_XA_LDO_BMC	1.1	0.451

 

[2informaticos]

Seems to have a problem around U3200.
Check all adjacent resistors; may need to change the chip also.