How long do the CCFLs in typical LCD flatscreens last?

[Guden Oden]

Just curious, my monitor isn't even six months old yet so there's hardly any panic on this front yet. Still, would be interesting to know.

Also, are there usually one or two of these things in a monitor? I'd guess there's one at the top and another at the bottom, but that's just a guess. I suppose there might be just one too...

Finally, how much does it usually cost to replace these things, and do I need a specific tube for my particular brand, or is there some kind of universal standard (depending on the length of the tube/width of the screen)?

 

[Albuquerque]

I have a Thinkpad 600E that has lived for eight years through several moves, a ton of travelling, and countless thousands of hours of powered-on time. It's just a tad dim and slightly pink when you first turn it on, but within about five seconds (ie after the POST screen is done) it clears right up and works fine.

I'm sure it's getting closer to it's last leg, but it's not there just yet. I'd wager at least five years of constant-on for the newest models...

 

[PC-Engine]

About 50,000 hrs til halfbright.

 

[JBark]

I've had my laptop for close to 7 years now, and it still seems pretty close to the same brightness (which was sucky when I got it). The light has failed to turn on a couple times, but hitting the "lid closed switch" a couple times turns it on.

I've had my desktop LCD for 3 (maybe close to 4?) years now (Planar PV174) and the brightness seems fine on it too. However, I'm starting to get some sort of blemish up in the top right corner of the screen. Not sure what it is, but it looks sorta like someone pushed their thumb into the corner and messed up the screen layers. I know that didn't happen, so I'm guessing something is degrading up there. Barely noticeable, I only see if it something bright is up in that corner.

I'm pretty sure most screens need their own specific CCFL, but many of today's displays are made at the same factory, and the only thing different is the sticker on the outside.

 

[Frank]

The backlight can get dimmer or even stop functioning, depending on the type used. But the main problem is in the spacers. There's a whole lot of those spacers (tiny plastic balls) scattered inside the panel, to keep the distance between the front and back equal over the whole panel. When you press the panel, those spacers can damage the TFT elements, which results in damaged subpixels.

Otherwise, the pixels that survive the first week will probably survive a decade without any problems.

With some panels, replacing the backlight can be done, but in all other cases the whole panel is replaced, as it is much too expensive to replace the TFT panel itself (which is about 90% of the total cost).