Isolating MacBook no power issue

Hi Everyone,

I have a 13" Mid 2012 Macbook Air that has stopped turning on.

I have tried multiple known good chargers - no light on any of them.

SMC Reset, unplug battery + power button all did not help.

No activity at all upon powering on. There are NO battery status indicators on this model to tell if battery is charged at all..

I assume that it is either the logic board or the I/O..

Is there a way to isolate this between a faulty logicboard and a faulty I/O Board?

I understand the $90 I/O Board would be a better place to start then the $400 logic board - but was curious if there was anything I could do to test for sure which is the failed component. Is there a way to send power to logic board bypassing the I/O Board? It's likely the battery is completely discharged so I don't think shorting the pads did not seem to work, due to I'm guessing no power in the system.

Thanks in advance