A few weeks ago my secondary display (a Samsung 930B) went dark. No smoke, no fire, or any other spectacle, just work up one morning and it was dead. A simple flashlight test determined that the LCD itself was still OK since I could still see content on the screen, albeit barely. Life was a little chaotic so I simply set it aside and resigned myself to using only one screen in the interim.
This evening I finally got a chance to pull it apart and take a peek inside to see if there was anything I could do for it. Initially I suspected that the CCFL(Cold cathode fluorescent lamp) had gone bad. I made this assumption based on experience with LCDs in laptops at a previous job, having never seen a LCD use more than one CCFL tube for lighting the entire display. This first assumption did not change with my cursory inspection of the joint inverter and power supply PCB(Printed Circuit Board). There were no immediate signs of failure such as scorch marks or visibly damaged components, and no telltale smell of burned electronics. I set the PCB aside and continued to dismantle the LCD panel itself. Upon removing the LCD panel from the light spreader and extracting the CCFL mounts, It surprised me to find not one, not two, but four CCFL tubes. The CCFLs were grouped into two pairs, one mounted on the top and the other on the bottom of the panel.
Potentially failed capacitors.
The likelihood of all four tubes failing at once is astronomical, so I reexamined the power supply and inverter circuit board. Rather quickly I noticed 3 capacitors in the corner with bulged tops. Further searching on the internet led me to a forum post on Badcaps.net. There another user had met nearly the same problem as myself, with the same model display. That user’s fix was to replace all the capacitors on the circuit board with new higher quality (and higher capacitance) ones from Digikey.
In the mean time I have also learned that the CCFLs and inverters used in common PC lighting kits are nearly identical in design to those used in LCDs. To test the LCD inverter or CCFL, you simply connect them to their counterpart from the common lighting kit. This provides a cheap and simple method to determine if the failure is either the LCD inverter, or the CCFL. As I was never much into the PC modding scene, I do not have one of these kits and will need to acquire one before continuing.