LCD Backlight Trouble

[zer0x]

Hi all,

I have a spare machine running OpenBSD with an integrated LCD panel (so I can't turn the screen off without a screwdriver!). I seem to be unable to disable the LCD backlight. No matter what I try, the screen will blank but the backlight remains permanently on.

Both dpms via xset and wsconsctl do nothing but blank the screen, and xrandr's --off has no effect (as well as only reporting 'default' output).

I have had similar problems in Linux, the solutions being to use the nvidia blob, or vbetool in console.

The machine is still on 4.4 RELEASE, and I will be trying a recent snapshot soon, but I am not really expecting that to improve the backlight situation.

Someone did suggest that setting an absurd modeline e.g. 1hz refresh rate, would cause the screen to turn off due to no signal, but that seems like a very dirty solution if at all. Saying that, I am getting quite desperate, and very much appreciate the suggestion!

I was just wondering if anyone might have any other suggestions or comments before I consider switching it back to Linux or grabbing the screwdriver?

Cheers,

zer0x