Original post by: ABCellars ,
Due to the age of the machine, along with the flickering you mention and with changing the brightness level sometimes bringing life to the backlight 90% chance the CCFL bulb in the LCD has reached it's lifespan. The other 10% inverter cable or inverter. The CCFL bulb can be replaced, but it is not an easy job. Most people chose to replace the entire LCD. New LCDs for these are available on eBay for about $70USD including shipping. To test the inverter cable. Preform a continuity test using an analog multimeter/multitester (One with the needle.) while moving the wires around. Do this for each wire in the cable. If the needle sweeps hard at any point, it is a break in the wire and the cable needs replaced. Digital multimeters usually have to slow of a reaction time for this type of test and/or have circuitry in them to ignore quick fluctuations in a reading. One way to test the inverter, if you have a multimeter that can measure frequencies of 50k or more, take a piece of paper and use it as an air gap between the probes and run it along the lower bezel if you get a measurement of around 30k towards the center your inverter is good. Inverters are cheap enough to buy one to swap out to be sure it is not the problem.