early 2015 MacBook Air LCD is there an inverter board?

Dear IFixit reader,

I have an A1466, Early 2015 MacBook Air, whose LCD assembly was replaced and it still exhibits the same symptoms before replacement.

This begs the question, is there a separate inverter board attached to the motherboard, or does one have to replace the whole motherboard to fix the problem? I attempted zapping the PRAM, resetting the SMC, attaching to an external display (which worked), single user mode, open firmware, but all result in the same problem, very dim unreadable display.

Disconnected the battery each time, held the power button down 30 seconds, and still no change.

Thank you.

Sincerely,

A tech repair person