No power or charge

I got an iPhone X to repair which had a damage screen and did not turn on when connected to power so I opted for changing out both the screen and the lightning flex connector. Replacing both results in the same thing happening, I hooked it up to a USB voltmeter and the output goes every couple seconds from 0A to 0.08A. Using a wireless charger also doesn’t do anything although it says on the charger that it is giving charge. Could anyone help me in further addressing the issue and whether it is repairable without resorting to motherboard micro repairs. Thank you.

EDIT: the battery has also been replaced with no success.