820-01700 No power (20V, 0A)


New member
I have a 2019 16" MBP (820-01700-5) that will not power on. 20V 0A. T2 is not booting and is not recognized by Configurator 2 in normal or jumpered DFU mode. I strongly suspect a short, but cannot find one.

PPBUS_G3H - 12.3V
PP3v3_G3H_RTC - 3.3V
PP3V3_G3H - 3.3V
PP1V8_SLP2R - 1.8V
PP1V1_SLPS2R - 1.1V
PP0V8SLPS2R - 0.8V

PP1V2_AWAKE - present
PMU_SYS_ALIVE - present
PMU_COLD_RESET_L - present
PMU_ONOFF_L - present

I2C_PWR_SCL - not short
I2C_PWR_SDA - not short
PP2V5_NAND_SSD0 - not short
PP2V5_NAND_SSD1 - not short

All power attempts done with battery and BMU cable connected. Both were replaced by Apple recently. I also replaced u7000 and checked all surrounding resistors and caps. I'm fearing the T2 itself is bad. Have I missed anything? Any help appreciated.


New member
First of all, welcome to the forum!

Any history available?
Check UPC_PMU_RESET level.
Thank you! I have been a lurker for several years just reading all that I can, but I'm starting to have newer machines that elude me.

No history for this computer. Under the scope when I got it it looked very clean, no traces of corrosion anywhere that I could see.

UPC_PMU_RESET is 0V without a short. Inputs to U6940 are good.


Staff member
PMU reset is good, so must be other problem.

Looks like T2 internal issue.
The machine should be recognized in DFU, if all AWAKE and SLPS2R voltages are present.
Did you follow all the steps in DFU tutorial?

BTW, write directly into reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above...


New member
True. Bad habit!

I have tried DFU steps many times. Will it enter DFU mode even if NO current is being drawn? Does the battery have to be connected, and BMU cable?

Is the keyboard bad? Is the T2 itself bad? Can this be replaced, or is that foolish?


Staff member
No battery needed for DFU.
5V on USB-C input is enough.

The board can be forced into DFU without keyboard.
Just tie SOC_FORCE_DFU to 1V8_AWAKE.


New member
This is a very long shot--bear with me--I have an a1990 that I believe the T2 is fine on. Can I replace the A2141's T2 with the one from the a1990? Ignoring the complexity of the BGA work--would it work?


Staff member
Very likely not.
We still expect someone to do such thing and let feedback on the forum.
However, need to take T2 from same model donot board.
Also, keep in mind, chip ID is baked into T2; no way to change it.
Last edited: