Top LCD tinted purple, bottom LCD blank. Turns off when hinge turned.

Hi!

Well, this could be multiple things tbh.

But first open it up and check the screen cables. As far as you said, the touchscreen is still working fine. It's just the display only.

Purple screen can indicate that the cable is having tears... Then the top screen need to be replaced.

For the lower screen, make sure that the ribbon cable is all in the connector (when it's not even fully in, it can cause issues). Please take it out and clean everything first, then put it in and try again. If the screen is still black, it probably need a replacement too.

Regarding the "pop" sound when you open the hinge further, is most likely caused by the damaged/teared upper screen cable (thats why that screen needs a replacement anyway).

And at last, it also could be a motherboard issue (saw this earlier) which can cause a purple screen. So make sure the motherboard is all cleaned too. Could be a GPU issue and then the motherboard need to have a replacement as well...

The best thing to do at this moment is to take it out and clean it. First replace the lower screen to see if it want to turn on again. If it's still doesn't want to turn on, then replace the motherboard and check again. When the motherboard is replaced, check the top screen if it's still purple or not, if it is still purple, then that screen need to be replaced as well...

Good luck!