Know anything about LCD backlights?

[dudi]

The backlight on my LG 26LC2R telly box has developed a fault and I'm trying to figure it out, so if anyone has any know-how, your help would be appreciated.

When I switch the telly on, the screen is fine for about a second, then it goes blank - the backlight has switched off and the picture is not visible.
If I hold a torch up to the screen I can see that the picture is still there, it's just not illuminated. the audio is fine, and the backlight works for a second very time I switch it on - no matter how long I leave it.

from this I am guessing that it's not the light itself, but a power supply problem. and the fact that it works OK for a second leads me to think it's also not a fuse problem.

Could it be a capacitor that's not discharging as it should be? or might it be something overheating?

I'm fairly capable of fixing the problem (I think... as i'm pretty handy with a soldering iron), but I am having a mare of a time diagnosing it in the first place!

Any suggestions on what to look for would be a great help. I would like to repair it as the picture quality on this TV is amazing, when it works!

** it's not unter warranty any more, and I haven't called out a TVrepair dude yet as they cost a fortune!

 

[Carwash]

I had the same problem with a laptop screen a few years ago. I just took it to be repaired, but I think it was just a loose connection somewhere. Sorry not to be more helpful!

 

[simonali]

Aren't LCD backlights like fluorescent tubes? There could be a problem with an ignition circuit that fires it up or the flicker you see might be the starting circuit going and not lighting a dud tube?

This is all guesswork btw!

 

[marinyork]

It'll be the inverter or something annoying the inverter. It's not necessarily that hard to repair but you will need to the tv to bits.