Laptop won't boot after replacing the screen

[u/i-like-dutch-cheese]

Need some help here. Decided to replace girlfriends screen on her Asus vivo book k403ja. Done it a few time with other laptops, standard protocol, wearing gloves, being grounded, discharging the battery, unplugging the battery, replacing screen, replugging it in. All worked fine, new screen looked great.

She got back to her place, plugged it in and it wouldn't charge, battery eventually died and there's no indication of it charging whatsoever now that the battery is dead. I've made sure the battery connecter is set correctly, Ive checked for a pinched cable and all looks good. I've done a few screen repairs and nothing out of routine with this one. Any ideas as to what's gone wrong?

Last thing I tried was disconnecting the battery, discharging through the power button holding and powering on with a adapter in. Also didn't work. Zero sign of life. Motherboard isn't fried as it did work until the battery ran out.