White display on my lg flatron L192ws
Most common problems with LCD monitors arises due to weak or damaged capacitors. Disconnect the power and signal supply from monitor, then open the case gently. Use a flat screwdriver for pry opening the case, after removal of screws. Here you have to look for faulty capacitors on the circuit. On the PCB of the monitor, check each capacitor for deformation/leakage around it. In case of any doubt, it's better to replace the capacitor, as they are inexpensive. The only thing is that you should use the correct rating capacitor for replacement. You will need a soldering iron, and at best a multimeter for carrying out the job. After doing all this, assemble the monitor back, and your monitor will be working fine.
Caution : If you are finding yourself uncomfortable with all the work doing yourself, then ask for help from a qualified technical person.