Cant adjust screen brightness!

Just bought a brand new Lenovo ThinkPad W500 with Windows 7 64 bit, found I couldn't adjust the screen brightness.

When press the Fn key for adjustment, the sun logo for brightness will display on the screen, and the bars which show the brightness extent will increase or decrease, BUT, the screen brightness itself doesn't change.

Then I do this in the control panel. It doesn't work, either.

Then I recover the laptop to factory default. The brightness still cannot be adjusted.

When the laptop is turned on, normally the brightness is in the maximum state. Occasionally it is very dark. But the brightness can not be adjusted regardless of what the initial state is.

There are two video cards in my laptop, on Intel one and an ATI one, switch enabled. The driver has been updated to the newest one.

Will any one have any clues what is going on there? Is this more likely the Windows 7's or the ThinkPad's problem? Would this be a hardware related problem?

Thank you very much!!!

Rick

i've had a w500 for about a year and had no problem with screen brightness. last week i upgraded(?) from vista to windows 7 64 bit and can't adjust the brightness. i don't even get the controls on the screen as you've described. interestingly (and annoyingly), the fixed state on mine is the dimmest setting. i can barely read the screen.

anyone figured out how to solve this?

This link contains some solutions that others have found although I'd have thought that something like a bios update would be the key?

Anyway here's the link: Help! Brand new W500 cant adjust screen brightness... - lenovo community