¿Why my ipad7 is not turning on?

I come here searching for information and help to repair my wife's IPAD 7 WIFI-2019, model A2197. Iam not expert in phone repair, but i want to learn, so i am reading and searching information.

I sent the ipad to a techincal service, but they did not repair it, so i am trying to fix it. The problem is the IPAD is not booting and no turn on.

This is what i found until this moment:

1) with battery connected, the current draw from the power supply is about 450mA from the charging port.

2) no short circuit in lines VCC_MAIN, VCC_BATT.

3) with the power supply, or with the battery, the 3.7V of VCC_MAIN and 1V8_ALWAYS are generated without problem.

4) the current draw from the power supply, without battery, is about 26mA from the charging port.

5) i haven't the diode mesurements of the main lines if power, so i dont known if i have a fuge in VCC_main or other line of principal power.

6) i dont know what other test or action i have to do to diagnostic the fault.

I'll appreciate so much your help.

God bless you, and thanks for this forum.