A1990 820-01814 P5V_G3S missing

[sese2504]

Hello Guys
My MacBook Pro a1990 820-01814 has no power
It takes 20v and around 0.06A but it's cycling to 0A
All 5v rails are missing
P5VG3S_en_r , P3V3G3H_EN , P5V_3V3G3H_en are also missing

The PMU is getting 3.3v but it doesn't output PMU_PVDDMAIN_EN which is responsible for these enable voltages above.
Any Tipps?

Thank you

[sese2504]

Re: A1990 820-01814 P5V_G3S missing

I measured the SSD Voltages
PP2V5_NAND_SSD0 is 0V
All the other SSD voltages are also 0V but no short
Any Advise?

[Stephen]

Re: A1990 820-01814 P5V_G3S missing

Sounds like a bad T2. I believe mine had the same issues and it pointed to a faulty T2 chip.

[sese2504]

Re: A1990 820-01814 P5V_G3S missing

This is a answer I expected but don’t want to hear:/

DFU is working but it can’t complete the recovery (ssd no voltage)
Is there anything I could check maybe the i2C bus?

[mon2]

Re: A1990 820-01814 P5V_G3S missing

if you suspect the I2C / SMBUS lines, remove all power.

Meter in DIODE mode.

Red meter probe, yes RED to ground.
Black meter probe to the SCL line of the I2C / SMBUS interface.

What is the voltage reading ?

Repeat to test the SDA line of the I2C / SMBUS interface.

Post each measurement.