820-01987 Freezes on apple logo

Omanyd

New member
Macbook Pro 2020 Intel 820-01987

Hi! This Mac was filled with liquid and in the previous service it was cleaned of dirt. The Mac started to turn on, but after 5-7 seconds it turned off completely at the apple logo. I cleaned it up again. It had the J6801 trackpad connector torn off and I soldered it back on. After Revive in DFU, the computer began to enter the Recovery download window and asks to connect to a Wifi network (DFU via Air M1). If you enter the password for wifi, then the Mac will freeze tightly in a few seconds and will not react to anything. It may hang during the process of entering a password or choosing a network.

In the previous service it seems that U6903 was soldered, but I did not notice anything suspicious anymore. There are no signs of corrosion on the board. Booting from an external drive does not work, it just hangs on the apple logo until a disk is selected. Tell me what should I do next? What should be measured? Consumption on the USB-C tester when the Mac freezes 673-680mA. Thanks!!!!

When the Mac freezes when entering a password:
PPBUS_G3H = 11.045v
PP0V95_S0_CPUVCCIO_REG_R = 0.954v
PPVCCSA_CPU_R = 0.806v
PPVCC_CPU_PH1 = 1.113v
PPVCC_CPU_PH2 = 1.116v
PP3V3_G3H = 3.302v
PP5V_G3S = 5.114v
PP3V3_G3S_WLANBT = 3.305v
PP1V8_G3S_WLANBT=1.802v
 

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2informaticos

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

Did you try DFU restore too?
It will erase SSD, but may be last option.
Check if is possible to recover data in Target Disk mode, if needed.
 

Omanyd

New member
Yes, I have tried this. The last time ended with an error. Only Revive passes without problems.
 

Omanyd

New member
I can't get into Target disk mode. There is no reaction to holding the T button, it just loads into the wifi connection window
 

2informaticos

Administrator
Staff member
I suppose an SSD issue, if you can't finish DFU restore.
Should be good to test the board in known good shell, to discard accessories problem.
 

Omanyd

New member
With the lid closed and external display I started entering recovery but stopped after an hour with an error -2003f. I made another attempt to revive and restore but both failed. now poppy 20v 30-60mA and nothing more. very strange1322541E-8A9D-49A2-8272-B0D0531C0BA1.jpeg910FFF1A-0AA7-49F7-A12D-5C5DE155B96F.jpeg
 

2informaticos

Administrator
Staff member
Disconnect internal LCD (J8500), don't keep the lid closed.

You can't go ahead before complete DFU.
If now lost image and fails even Revive, may have T2 internal problem, or SSD.
 
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