Brightness jumps to maximum while on battery

Hi guys,

Sorry if the post goes to the wrong place.
I've bought new laptop recently, everything works great, but there is still one problem. If I am working without the charger, on battery, the screen brightness always jumps to maximum. I have it on 30% in my power plan, and there it stays as 30%, but the brightness is still on maximum. If I press FN+F4, I could decrease it for a couple of seconds, and then it goes up again by itself...

I have tried all possible settings in Windows, also have downloaded all new drivers (but there are not a lot of them as Inspiron 1564 is new model). I have found one possible reason also, there should be "Display Brightness" field in BIOS, but there is no such option in my version of BIOS.

Any ideas? Help would be really appreciated!!!

Tepid said:

I am calling this a definite BIOS issue.
Yeah,, they are only on Version A01 of the BIOS,,, this will probably be fixed in a BIOS update.
Contact Dell and tell them of this so they are aware of it.

Yep, I do think on BIOS either. There should be such option for Brightness as User Defined, and by default it is Auto. But poor me could not change it because of limited BIOS.
I have informed our local, Estonian, Dell, but they are too shy to inform somebody else, their answer was to wait till somebody from bigger country take care of it.
As for bigger countries, I have sent an e-mail to England, no reply form there. I've tried to speak to Dell support in USA and in Netherlands, but both didn't want even to listen, their answer was that the pc is from Estonia and they will not help =(
SO, hopefully, I will be not only one with this problem...

I am having exactly the same problem! Sooo annoying! I bought mine from PC world and am going to take it back there to see what they suggest.

Saying that, I have just tried a fix from the following link and it seems to have worked - fingers crossed!.
Dell Inspiron 1564 brightness jumps up while on battery without any reason - DELL COMMUNITY

I have the same problem on ASUS F3ke, OS XP.
I've solved this in
"Device Manager->Monitors->Plug and Play Monitor->Disable"
Just curious whether this works for you.
R