It sounds more like it could be the backlight itself, rather than the inverter. The inverter tends to either work, or completely fail. It produces a fairly high AC voltage for the CCF fluorescent tube which is behind the display. That tube has a finite lifetime; you generally will see the screen brightness slowly go down over time, and eventually, it may fail completely. This is more or less like a fluorescent light tube you would find in an office building etc. Only this one has a "cold cathode", meaning it does not need to have a filament inside of it constantly being heated by electric
