820-01987 dead

2informaticos

Administrator
Staff member
That means PPBUS_G3H is not properly controlled.
U7000 needs to communicate with T2 for this.

You may have a problem with I2C battery bus, or T2 corrupted software.
Try DFU revive first.
If no important SSD data, go for restore; if revive didn't help.

If can't enter DFU, check if all AWAKE and SLPS2R voltages come on; at corresponding small coils around U7800.
 

BlueGold

Member
Okee i cant enter DFU the device is not booting. No fan spin nothing.
i Checked I2C_PWR_SCL and SDA they have 1.8V.

i checked the awake and slps2r lines they are fine too.

I hope you have some new ideas for me.

and sorry i am a beginner in Macbook repairs
 

2informaticos

Administrator
Staff member
Did you force it correctly?
Must close it before connecting charger and maintain the short several seconds.
 

BlueGold

Member
i think i did all correctly. I short 1V8 to Force DFU and connect typ C cable to host macbook. I did one more measurement and noticed that the macbook havent voltages when the battery is connected. What do you think about that? I have only when the cable is connected.
 
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2informaticos

Administrator
Staff member
Connect both charger and battery for DFU.
Some machines don't complete DFU without battery.
Be sure to use dedicated USB-C port for DFU.
 

BlueGold

Member
Hey i have some news,

I solder the old U3100 Chip and now i have dfu. A lot of terrible chips are on the market. Pretty unlucky.

So now i tried to restore the macbook and i got amrestoreerrordomain – 0x6 (6) Error.
Do you know whats wrong now ?

i read that it can be the nand chip.
 
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