Can someone tell me what a laptop LCD Inverter do?

Laptop inverter provides power to the backlight.
Normally if your screen lights up then the inverter is in a job.

Provided your are considering replacing the screen after taking the blind apart is going to crop up anyway - so take it apart and supervise the picture cable from the rear of the eyeshade to the motherboard. Disconnect/reconnect.

You could also reset the color harmonize on the screen. If you have either NVidia Or ATi or Intex Express graphics chip then there module be a cartel sheet application which will include color tuning options.

It might just oblige the ruby brightness or letter to beryllium turned down - or the green brightness whether gamma to be turned up.