[QUOTE=Dartman;2575568]Sounds like the back-light is bad, or the circuit driving it has issues. I’d do all the steps suggested and make sure it’s the monitor then you can decide if it’s worth trying to fix or not. You can find replacement back-lights on Ebay and other places but if it’s not the light itself or you don’t have any experience soldering and working on electronics it’s probably faster and cheaper to get a good deal on a new monitor.[/QUOTE]
On a notebook computer it’s more usually the “inverter board” that has failed.
the inverter board" is the power supply for the cold cathode Flourescent backlight.
If you do a search on ebay for “inverter board”, "your Notebook model"
you’ll likely find a dozen people selling them
If it’s a desktop LCD monitor try another EXTERNAL power supply and if that isn’t it I’d start monitor shopping.
When your old one is already dead is the perfect time to shop for a bigger monitor.