W700ds backlight shutting off

[winkoe]

Greetings to you

On my W700ds the backlight of the main display is shutting off after several seconds. However if I dim the display via (Fn + End) the display keeps on working. BTW external monitors are not affected.

Naturally I suspect the inverter card. But the monitor having two backlights, would both backlights fail if one transformer is faulty?

Before getting into the trouble to obtain a replacement inverter card I wonder if the driving signal for the card could be the cause.

Any suggestion how to proceed?

Vin

[kfzhu1229]

The main screen of the W700 also has two backlights to achieve 400 nits of brightness. This is called Dual CCFL.
I do have horrible luck with CCFL backlights from these mid-late 2000s Samsung panels (which is the only model that comes with W700ds series). It is possible they are simply not as durable as the likes of LG Philips or AUO for example.
I do suspect that at least one of the two backlights in the main display is faulty. All of the times that I've seen backlight shutting off at high brightness is because of faulty CCFL tube.
Unfortunately it's not exactly easy to find a compatible backlight at a respectable price, nor is it easy to replace, and nor is the screen going to be perfect after replacement. There is also the small risk of poisoning yourself if you do end up break one of the tubes and don't take the right precautions. But also since I imagine such a screen isn't going to be particularly cheap at all, I guess it is your call.

[winkoe]

Thank you kfzhu1229

yet both backlights are on if I select low brightness. And only if I increase the brighness control gradually they will fail simultaneously a few seconds later.

Vin