So, your computer monitor is really dark or faint, and changing the brightness (using the ‘Fn’ key, for example) isn’t working. Now what to do? Simple. If you have a multimeter with a KHz option, use that to test the inverter. A cheap multimeter will register the KHz differently; if your multimeter KHz option only goes up to 20KHz, you may get a ’1′ as the result. This means the reading was ‘off the charts’…too high for the cheap multimeter to register the proper KHz. If you are looking for a good multimeter, consider the Fluke 110 true RMS meter, as its KHz rating goes up to 50KHz. The reason we want to test the inverter first is because the cost of inverters is low, so we can rule the inverter defective or not before moving on to the pricey LCD or backlight repair.

Take your multimeter, and set it to the KHz notch on the dial. Now, with the computer on, put the multimeter tips close to where the inverter would be (usually towards the bottom of the LCD housing), about a half-inch apart.

Replacing an LCD backlight is not an easy job. On a scale of 1 to 10 of DIY repair, I would rank it an 8.5. Replacing a dead backlight is a cost-efficient way of repairing an LCD without breaking the bank. Most backlights run $4.99-$15.00 (shipping included) on a site such as eBay, and some LCD’s even have two backlights, so make sure you order the right amount.  Otherwise, you might be waiting another week with a dark or dim screen, and nobody wants that.

CompuTechs+ does not recommend replacing the backlight yourself, but if you are determined, here are the steps:

Replacing an LCD Backlight is a requires extreme patience, as it is a fragile process. Not only is the light itself featherlight, it also contains the hazardous element mercury.

1) Remove the LCD from its housing (if you don’t know how to do this, please do not proceed)
2) Remove all the screws you can find located on the LCD, and carefullyremove its casing
3) Finding the backlight(s): LCDs typically have 1 backlight, some have two. The backlight is a very thin, long CCFL tube (which is typically located with rubber ends, and is connected to the cable coming off the inverter.

4) Once you have determined if the LCD has one or two backlights, now its time to get the replacement backlights. CompuTechs+ recommends replacing both backlights (if your LCD is a dual-backlight monitor), it will save you a big headache in the future. Either search for your LCD model number on eBay, or measure out the backlight to find a correct fit.

5) Be careful installing the backlight, remember that when you are removing the LCD layers for replacing the backlight that you need to keep the LCD layers together. If you don’t, they might be difficult to get to line up easily again.
6) Put it all back together (test before completely reassembling), and enjoy your bright, cheaply fixed component!