Something I have seen in several brands of laptops lately is that the connection between the FL harness and the FL inverter becomes "corroded". I don't know if it is from incompatible metals or connections that are experiencing arcing. To see if this is the case, open up the LCD module and reseat the connection from the cable to the FL inverter, not from the FL inverter to the FL tube that is in the screen, a few times and see if your problem goes away. If it doesn't, then your bulb is probably going out. It is possible that the FL inverter is going bad, but most just go out completely.