[nmglug] screen brightness

[akaluta]

Esteemed persons of  Glug;

Sudden laptop screen brightness reduction.

Dell laptop Ubuntu 12.04 lts 32 bit.

12.04 has been installed,problem free, now several months

Yesterday sudden reduced screen brightness,about level when running on 
batteries alone.

Solutions tried;
    1.)  System brightness adjustment.

    2.) Installed backlight - set to 100

    3.) tried xradr -output LVDS1 1.0

i welcome your insight.

Best

Anthony