lenovo y700 1th mobile tablet problem

[limpidity]

The tablet is not working.

This model is equipped with a Snapdragon 870.

Pressing the power key using the DC power supply increases the current to 0.14a and returns to 0.00 when the power key is removed.

CPU, RAM, EMC, and rebolling.

The symptoms are the same. I think there's a problem with the RAM, is that correct?

There is no short in the other part, and there is no problem with PMIC.

The same 0.14a comes out when removing the ram

[FriedFred]

The first steps of booting are provided by the EC chip. The Embedded Controller chip handles the startup-sequences of the mainboard. Usually, the current consumption is about 60mA or so. But 140mA is not a dead-short. So something needs some higher current, but it doesn't lead to a booting of the entire system.
I suggest to check-out the EC chip and the signals surrounding it. Especially the I²C-bus and SPI-bus. If there is not any traffic on those data lines, then maybe the EC chip has an issue. The EC chip itself can be damaged, or the memory content of the connected SPI-EEPROM can be corrupted.