Source for monitor backlights ?

[Jethro_uk]

As a last throw of the dice, does anyone know if it's possible to get replacement backlight (panels ?) for Dell monitors anywhere.

eBay seems to have PSUs and mainboards, but no lights ?

[Bob Minchin]

cpc used to do the tubes. Not checked recently.

Based on your earlier question I would say it is an extreme coincidence that a power cut has taken out a tube but more likely the surge has borked the inverter.

[John Rumm]

Is the cold cathode tube backlight or LED?

If its a bit older, it will likely be the tube. The don't often fail directly, but the inverters that drive them do. You may be able source one as a separate board - or often the function is built into the main PSU board. Either repairing or replacing the PSU may fix them.

With more modern LED backlit screens, then the LED chips in the backlight can fail. When they do, the proving circuitry in the PSU will often shutdown the backlight due to the load being out of spec. With the LED ones, the illumination is often done with an array of LED chips mounted on a number of PCB strips that run across the display (behind a diffusion layer to give an even backlight). You can test each strip in isolation (two or three PP3 batteries in series will normally serve as a power source for lighting a strip). Then either replace non lighting strips, or simply remove the failed LED from the strip (at the expense of a slightly dimmer bit of screen in its locality)

Got a link to a picture of the PSU - that will likely tell us what kind of screen its powering?

[NY]

I had a problem with one of my previous laptops where the light stopped working: the image was only visible (faintly) by reflected light shining onto the screen.

I replaced the inverter circuit as being the easier and cheaper to replace, but this did not cure the problem. So I bought a new cold cathode tube. That is where the problem began. The old light (a cylindrical strip) was taped to the edge of the screen, and I could not position the new tube sufficiently accurately along the edge to make the illumination of the screen even. I ended up with a screen whose brightness varied in bands across the screen, where the tube was in a slightly curved sinusoidal line instead of being absolutely parallel. The alignment appears to be utterly critical, and the slightest deviation is very noticeable.

It would have been so much better if the screen had had a metal guide into which the tube was slotted, rather than just being laid along the edge of the sheet of glass and then held in place with tape.

[John Rumm]

Worth mentioning that laptop panels and desktop ones can be quite different. The laptop LED backlit ones don't have the separate illumination strips for example.

[87213]

It is much more likely the PSU for the backlight that has failed rather than the light itself. Particularly when you say that yours does come on briefly and faintly when turned on.

[Thomas Prufer]

You've tested it's the light that's broken? ISTR you press a flashlight against the screen, and if the screen works, this external light will show the graphics etc.

Thomas Prufer