...hope this helps you..

_________________
...!!стучитесь....и вас откопают...
...!!knock.. and you will be dug up...

I understand that the person who regularly repairs laptops knows the exact procedure and therefore does not even need a schematic.

Here you have provided me with part of the schematic of the Asus X553MA although this is also useful but if someone had a schematic for the Asus X551MA it would help me.

PS
Anyway, if anyone was willing to advise the diagnostic procedure, I would be happy.
The fact is that 19V from the power supply gets only the first two FET transistors.
Nowhere else is there a voltage of either 3.3V or 5V which is logical as it has nothing to open the two FET transistors.

Интересно. У меня с батарейкой то же. Все напряжения после включения присутствовали, но старта не было. Проц холодный. Прошил биос - не помогло. Вытащил батарейку, замкнул контакты холдера батарейки, вставил. Все заработало. Чудеса однако.