Hi, sorry for the delay, but not sure if there's a lot of people taking apart their systems these days, so sometimes it can take more time for the right people to run across your post.
If you trust it, you can also probably find your answers on the internet too, but it's always great if someone can talk you through it of course.
Anyway, expect there should be some G750 disassembly videos out there (?) that are probably similar enough to your G750JM model if there isn't one specifically available for it, but you should find the G750JM uses a separate LCD cable, so yes I would suggest trying to replace or even just reconnect that cable before spending money on an LCD replacement.
Guessing that finding an LCD cable for your unit may be the toughest part though, but hopefully I'm wrong about this and there might be other models using the same LCD cable.
Was thinking if you did end up sending the unit to ASUS for repair that you try to make sure that they check the LCD cable first before replacing the entire LCD, but honestly not sure how easy or well this will work and how good the communication will be, but it's an idea anyway.
You probably know you can attach an external monitor temporarily to use the system if necessary, but thought I would make sure.
Good luck and let us know how it goes if you can!
