iPad Pro 12.9 (4th Gen)

Problem DescriptionSymptomsSolutionSource
Not charging, no power.- If you have a tristar tester or lightning breakout board you should test that before attempting the following.

- Test with a known good battery.

- Replace charge port.

- If the above didn’t help you likely have a dead tristar.
Source
No power.Ampreader shows 5V 0.04ACheck for shorts around the USB-C controller IC CD3217B12.Source