820-01700-A no power, no DFU

[iClub]

Using original 96W charger
Does not enter DFU
No history.



PPBUS_G3H - 12.63V
PP3v3_G3H_RTC - 3.38V
PP3V3_G3H - 3.38V
PP1V8_SLP2R - 1.79V
PP1V1_SLPS2R - 1.1V
PP0V8SLPS2R - 0.79V

PPVDDCPUSRAM_AWAKE - present 0.8V
PPVDDCPU_AWAKE- present 0.53V
PP1V2_AWAKE - present 1.2V

present PMU_COLD_RESET_L - 1.8V
present PMU_ONOFF_L - present 3.35V

I2C_PWR_SCL - not short 1.8V
I2C_PWR_SDA - not short 1.8V
PP2V5_NAND_SSD0 - not short 2.5V
PP2V5_NAND_SSD1 - not short 2.5V
UPC_PMU_RESET - NOT SHORT OV


I have a feeling that the UB3100 may be influencing this.

 

[2informaticos]

All posted rails look good.Machine should enter DFU.
Be sure to follow all steps.

DFU Mode Restore (Macs) - LogiWiki

We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area

logi.wiki

Do you get voltage on the big coils?

 

[iClub]

I forced it into DFU mode using the jumper method. No DFU mode.
Voltages present in the coils. I compared it with another board that works.

 

[2informaticos]

"Voltages present in the coils"
Can we know which ones???

 

[iClub]

coil	Voltage (V)	Diode (V)
L9080/81	2,5	0,34
L9020/21	0,9	0,407
L9030	1,8	0,382
L7660	3,35	0,352
L7600	5,15	0,374
LA850/60/70	0	0,018
CA244	0	0,03
LA750	0	0,02
L7231	0	0,02
L7330	0	0,02
L7221	0	0,02
L7211	0	0,04
L7410/20	0	0,02
L8102	0	0,059
L7701	0	0,175
L6960/61	3.38	0,088
L9520/21	0	0,145
L9530	0	0,315
PPBUS_G3H	12.63	0,342

 

[2informaticos]

You forgot L9580/81.
Which are very important in this case, as you already mentioned bad readings on L9520/21.
You must get similar readings between SSD0/1 areas.

 

[iClub]

L9580/81
V 2.5 V
Diode 0.041V

 

[2informaticos]

0.041 in diode mode is very bad.
It denotes bad NANDs...