I have a vintage GD8000 laptop running Linux Mint 18.3, and I'm having trouble turning off the autodim feature.
I have turned off autodimming in Mint's preferences, and I have also turned it off in the GD8000's BIOS. However, the screen still dims after 90 seconds of input inactivity.
Is there a way I can turn off the autodim feature so it actually stays off?
I've observed a little more closely, and the screen is not precisely being dimmed, in the sense of backlighting remaining on but being at a lower intensity. The backlighting is turning off completely. (But the screen is still "painted" and can be partially seen in bright light.) I suspect this is not a Linux issue.