820-01987, does not boot, 20v 70mA

[iganas]

Hey there

I got this board with no liquid spill or any other signs, no knocked off components.

Initially it used to start with 20v 150-300mA, staying for a few seconds and then bootlooping.
I tried DFU mode, which it successfully enters, however it failed every single attempt to recover with "Failed to restore device in DFU mode"


After several unsuccessful attempts, it started giving a different error:


Then I placed it back on the bench and now it only uses 40-70mA without any bootlooping.
I already took some voltage measurements, please lemme know your thoughts.

Big coils are at:
L7670 - 5V
L7690 - 3.3V
L7030 - 8.6V
All other big coils at 0V

PP1V_PRIM 0V
PPVCORE_S5 0V
P5VG3S_PGOOD 1.7V
P3V3_S5 0V
PP1V8_S5 0V
PPVCCSA_S0_CPU 0V
PPBUS_HS_CPU 12.6v

PP_SSD0_S4E2_VPP 1.30-2.60V (pulsing)
PP0V9_SSD0_S4E2_VDD_PLL 0.90V
PP2V5_NAND_SSD0 2.50V
PPVCCQ_ANI_SSD0 1.80V
PP1V8_IO_SSD0 1.80V
PP0V9_SSD0 0.90V
SSD0_S4E2_ANI1_VREF 0.90V
SSD0_S4E2_ANI0_VREF 0.90V
PP1V8_SSD0_S4E2_AVDD18_PLL 1.80V
PP1V8_SSD0_S4E2_PCI_AVDD_H 1.80V

 

[2informaticos]

Botlooping could be caused by short on some secondary supply.
Did you check resistance to ground at all big coils?

 

[iganas]

Resistance to ground is 5-30Ω on all the CPU coils and 62Ω at L7702.

The board is no longer bootlooping after failed DFU attempts

 

[2informaticos]

I suppose something wrong with SSD and DFU cannot write the firmware partition.