- 1). Obtain a replacement backlight from a computer parts supplier. Obtaining a bulb designed specifically for use as a backlight can be difficult or costly, but purchasing a cased cold cathode bulb designed for lighting computer cases costs only a few dollars and can be modified to act as a backlight. Buy a tube that is as long as your display is wide (i.e., get a 15-inch bulb for a 15-inch display). See the Resources section below for good online resources to purchase bulbs.
- 2). In a clean, dust-free environment, disassemble the display and remove the back from the screen. The backlight will be located at the bottom of the screen. Pay careful attention to how the display is taken apart so you can reassemble it once the bulb is installed. Taking pictures or drawing diagrams may be helpful.
- 3). If using a bulb designed as a case light, now is the time to modify it into a functioning backlight. Carefully use wire cutters to cut the plastic casing surrounding the cathode tube near its capped end. Be extremely careful not to break the cathode tube. The tube is very fragile and will release toxic mercury vapor if broken.
- 4). Use a blow dryer to carefully heat the glue surrounding the leads. It will become soft and pliable. Work the wire leads and bulb free of the casing.
- 5). Remove the old backlight in its reflector from the display. Cut the wires connecting it to the monitor, leaving enough slack to splice in the new bulb.
- 6). Separate the old bulb from the reflector and replace it with the newly modified backlight. It can be mounted with the clear plastic rings that held the old light, or---if these were not saved---using a clear tape.
- 7). Solder the leads from the new backlight to the wires that ran to the old bulb. Return the bulb reflector to the bottom of the display. Turn on the monitor and test to make sure the new bulb is functioning.
- 8). Reassemble your monitor.
Source...