Internal display not being recognised after battery replacement a1543

Thanks for the response :)

Yeah it powers on. Works perfectly with the external monitor. No degradation in performance .

I tried resetting SMC & PRAM but maybe did so incorrectly

All internal connections look fine and logic board looks normal (don't know how to inspect that for problems but looks as it did before)

Will open it up again this evening and have a look through it

Good evening young sir,

I would recommend checking some of the fuses surrounding the screen region. I'm no rocket scientist (nor professional computer technician), however if my screen just randomly died that's the first area i'd investigate.

When you were conducting the repair, did the connection accidentally bridge and cause a sudden power-up and loss? That is something very dangerous for these laptops.