Water Damage Replaced Motherboard and Screen, still no backlight

So my missus dropped a glass of water on her Macbook Air (a1465 Mid 2013 model). It didn’t immediately fritz. Switched it off, opened the back up and let it dry for a few days. Switched back on, wouldn’t boot. Replaced motherboard. Booted but no backlight. Replaced whole LCD assembly, still no backlight. Have I just been unlucky with my motherboard and/or display assembly; or is there something else that could be going on here?

Have done SMC and PRAM reset, still no dice.

Strikes me that there’s nothing else in the chain.

Help?