820-01598-A DFU/RECOVERY

[mbcontrol]

I'm working on a 820-01598-A which came with liquid damage - primary as a data recovery job.
I cleaned the liquid damaged areas. The logicboard pulses 63-64mA.
C6404 Pin2 is completely gone so i took the cap away - i think it's not necessary for data recovery?

The board shows no reaction. Here are my measurements ...

PPBUS_G3H = 12,600V
PP3v3_G3H = 3,307V
PP1V8_SLPS2R = 1,804V
PP1V8_AWAKE = 1,804V
PP1V1_SLPS2R = 1,102V
PP0V8_SLPS2R = 0,798V
PP3V3_AWAKE = 3.306V
PP1V2_AWAKE = 1,199V
PMU_PVDDMAIN_EN = 3,299V
P3V3MAIN_PGOOD = 3,274V
PP3V_G3H_RTC = 3,007V
PCH_RTC_RESET_L = 3,007V
P5VG3S_EN = 3,304 V
PP5V_G3S = 5,128V

Then i wanted to check DFU (i have not much experience with this).
Normaly i would expect to see the DFU - Logo on the Display of the machine with Apple Configurator2.
But it shows me a Logo with REVOVERY. This Logo comes without pressing any Key-combination, only after plug in the data-cable (usb-c to usb-c). What does this mean? What is the difference between DFU and RECOVERY?
All functions i tried to use didn't work (restart, repair, shutdown, backup etc.)

 

[2informaticos]

Did you note liquid signs on J6600 connector/flex, or Touch ID?

Do you get any S5, or S3 voltage on the board?

 

[mbcontrol]

It looks like there is no S3 S5 voltage on the board ...

PP3V3_S5 = 0V
PPVPCORE_S5 = 0V
PP1V8_S5 = 0V

PP1V_S3 = 0V
PP1V2_S3 = 0V

On J6600 connector/flex and Touch ID i can't find any signs of liquid

 

[2informaticos]

Did you try to enter DFU as in the tutorial?

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...

boards.rossmanngroup.com

 

[mbcontrol]

I did it again: In the moment i plugin the usb-c cable between the two machines the Apple Configurator2 shows the Logo with RECOVERY (without pressing any key).

without paying any attention to that, I used the key combination from the tutorial (Mr.Macintosh) - then the Logo changes from RECOVERY to DFU.

Is it normal that he runs automatically in this recovery-mode? What can i do now in the DFU-mode in AC2?

 

[2informaticos]

I never saw this behavior yet.
Try first revive option; it will preserve SSD information.
If no luck, you may need to try restore; be aware, will erase SSD...

 

[mbcontrol]

The revive option brings an error ...
(AMRestoreErrorDomain-Fehler 6 - Failed to handle message type StatusMsg (Operation failed)) [AMRestoreErrorDomain – 0x6 (6)]

... restore kills the customer data.
Is there no other chance?

 

[2informaticos]

Restore will probably fail, as revive too.
T2, or SSD problems, if DFU can't be done.

Just in case, check if is possible to start in Target Disk mode.

 

[mbcontrol]

Start in Target Disk mode don't work.
i don't have a lot of experience with ssd problems, can you give me some starting help for troubleshooting

 

[2informaticos]

Do you get SSD voltages?

 

[mbcontrol]

Here are the voltages from the page "ssd support" ...
PP0V9_SSD0 = 0,901V
PPVCCQ_ANI_SSD0 = 1,800V
PP2V5_NAND_SSD0 = 2,520V
SSD0_S4E0_JTAG_TDI = 1,781V
SSD0_S4E1_JTAG_TDO = 1,770V
SSD0_SWDIO = 1,777V
SSD0_SWCLK = 1,783V
SSD0_S4E_JTAG_SEL = 0V
SSD0_S4E_UART_RX = 0,669V
PP1V8_IO_SSD0 = 1,800V
SSD0_S4E3_JTAG_TDO = 0,742V
SSD0_S4E_JTAG_TRST_L = 0V
SSD_BFH = 0V
SSD0_S4E_BOOT2 = 0,002V
SSD0_S4E_UART_TX = 0,770V
SSD0_OCARINA_LPB_L = 0,672V
SSD0_S4E0_UART_TX = 0,753V
SSD0_S4E2_UART_TX = 0,714V
SSD0_S4E1_UART_TX = 0,715V
SSD0_S4E3_UART_TX = 0,735V
SSD0_OCARINA_WP_L = 1,800V
SSD0_WP_L = 1,800V
SSD0_LPB_L = 0,679V
SSD0_RESET_L = 1,800V
SSD0_OCARINA_PFN_L = 1,800V
SSD0_VR_P2V5_EN = 1,800V

 

[2informaticos]

Did you take pictures with damaged areas, before cleaning?

 

[mbcontrol]

Here are pictures of the damaged areas - after cleaning with flux and heatgun. The filenames tell you the part/area. there are three pictures from u8600 with a hole in the underfill material - is this from the production process or could this be an damage?

 

[2informaticos]

If U8600 got affected by liquid, T2 cannot properly access its SSD partition...

 

[mbcontrol]

ok so you think this underfill hole at u8600 is from a damage and not from production?

What can i do next? Shall i get rid of the underfill and make a reflow or/and ultrasonic cleaning?

 

[2informaticos]

Your board has a damage caused by liquid more than sure; not 100% U8600, can be somewhere else.
You can try to heat all BGA chips with quality flux.
In case need to burn accumulated crap underneath.
If problem is U8600 related, that explains why T2 cannot complete DFU.