iPad Air 2 suddenly died

My iPad Air 2 suddenly stopped working.

Screen is black, will not charge.

Things I have tried so far include:

1. Hard reset many times
2. DFU mode (detected by iTunes and begins trying to restore but fails) many times
3. Leaving on charge overnight
4. Different chargers
5. Mac and PC iTunes

By testing the power input it draws about 1.2amps for a few seconds, then drops to 0, then repeats the cycle. Screen remains black. I assume this means something low level or hardware.

Would I be best to change the logic board first or something less drastic?