I've been diagnosing it and this is what I found: if you plug the cable, the iPad draws 0 amps according to my USB tester device.
From what I've learnt, this could be a problem with the flex charging cable or (most likely?) the Tristar chip.

After opening the device and examine it, it looks mint inside. I measured voltage on the battery terminals and it was reading 2.4V. I wanted to see if the iPad would turn on with a charged battery and I don't have any battery replacement so I pealed off the plastic and charged the battery with an external Li-Po USB charger (with the battery disconnected from the mainboard, of course). The battery got up to ~4.1V so I plugged everything and tried to turn on the iPad: no luck, still dead (and still drawing 0A). Should an iPad with a bad Tristar chip turn on with a good charged battery?

I also measured some caps on the board on diode mode. Everything seemed fine but a row of caps next to inductors, they are reading 0.014 voltage drop. Is this normal??

Any recommendations on what else should I checked? or if I should buy a Tristar chip and replace it?

Thanks!!