Hi pradkur and welcome to the forum.
The problem could of course be the inverter rather than the backlight itself. If you are unfamiliar with disassembly of notebooks, and your machine is out of warranty, I suggest that you entrust the fix to a reputable repairer.
If, however, you are looking for a DIY solution then have a look at this general guide.
Go n-éirí an bóthar leat
