Dell monitor

[CoogarXR]

Originally Posted by MIPS

With CCFL backlight replacement being part of my day gig, before you tear the LCD apart next time get a good high contrast wallpaper (I used the indian head test pattern) and then blast a light into the screen with a flashlight or desk lamp. You should get enough bounceback to tell if it's the backlights/inverter circuit or if the backlights AND the LCD are not functioning.

Backlights usually turning on then off are because most inverters now detect shorts or excessively heavy loading from tired tubes and will shut themselves off to protect themselves. I keep a variety of loose CCFL lamps handy so I can sub in and pinpoint which bulb is being the problem without dismantling the screen.

Back when I worked on flat screens a lot, I built a portable CCFL tube tester using an inverter board from a portable DVD player. It runs off a 9v battery. It has enough nuts to power just about any single CCFL tube. It won't completely light a super-long one (like a tube from a 50" TV), but it will light the ends, lol, which is enough to see if the tube is dead.