Macbook A1708 820-00840 not a start

[AlexVG]

Hi everybody

I have Macbook A1708 820-00840
It goes through all steps to start
exclude last steps power PPVCCCPU_S0G and PPVCCGT_S0G

Besides, no exchange on
CPU_VIDSCLK
CPU_VIDSOUT

However CPU_PWRGD is OK
CPU_PROCHOT is down.

I replaced SPI dump from here:
https://www.badcaps.net/forum/troubl...n-me-pram-bios
Unfortunately did't help me.

Would you help me please to identify the problem?
Thank you.

[mon2]

What is the voltage to ground of PPBUS_G3H?

[AlexVG]

13.5V

[mon2]

Do you have 20v on the type c meter and external power adapter?

What is the current draw showing on the same meter?

[AlexVG]

Yes.
20V
250mA stable

[mon2]

When you apply the power adapter, does the 20v immediately spike to 250mA stable or slowly climbs up to this value?

[AlexVG]

5V (1sec) - 7V (0.5 sec) - 20V
150mA (1sec) - 250mA