A quick google search says "about 30,000 hours or eight years of use at ten hours per day." for the backlight to reach 50% of original brightness. It sounds like you've babied your monitors so your's will likely stretch longer.
Thanks for the info, but the topic is about burn-in. A quick Google search shows this article: http://www.techlore.com/article/10099/D ... s-Burn-In-
It says burn-in basically won't happen on an LCD, though I've seen it on phones at the Verizon store (not sure if they were AMOLED or LCD though) and on an LCD monitor, which is why I worry about leaving UltimateBootCD running all day or night waiting for a scan to finish (I've had scans last up to 4 days). While I can't say I've had LCD burn-in, there's absolutely no reason UltimateBootCD should by default not time-out the screen, and the point of the thread is to bring this up as an issue to the community (since UltimateBootCD and other Linux boot CD developers don't seem to have realized this or care) and to find solutions.
Which is why I say test this! Most laptops I've come across do not require OS-level software to enable the dimmer shortcut keys. Some laptops will sleep on lid close, some will simply off the LCD (which is what you want, right?). Every laptop behaviour is different.....
I'll have to research it for whatever laptop I'm using, but the ultimate solution is just for these Linux boot CDs to handle monitors sensibly based on computer idle time. I don't know why they don't already.
Power management in Linux is highly dependent on modules compiled in at build time and BIOS support. Every module added can impact performance and compatibility in many unforeseen ways given the thousands of systems out there. Granted there are common building blocks and standards to make life easier but there are simply no way to validate every system configuration. For a system recovery and testing distribution like Parted Magic, (vs general everyday use distro like Ubuntu) I would guess the distro maintainer would choose to value stability and compatibility and only build in the bare minimum necessary to get the job done.
Does this mean no matter what the Linux boot CD developer does, there's a chance that turning off the screen while running can mess up the laptop or prevent the screen from coming back on? Some Linux boot CDs do this just fine with a default timeout and I've run into no problems with them across multiple laptops from different generations and manufacturers.
If this really means that much to you, give this a shot: https://bbs.archlinux.org/viewtopic.php?id=66169
Thanks, this is helpful and I'll try it, but it leaves me scratching my head because if this is supposed to work on any laptop, I don't know why a default would work any less. I imagine the number of models of laptops that a default screen timeout won't work with is few and far between, and the number of unrecoverable problems caused by it is probably the same or less than most other common things you can do on CLI that's incompatible with the laptop.