07-24-2014 11:35 AM
Hello everyone. I just purchased a new L540 with Windows 8.1 x64 on it and have run into a problem I'm seeing is apparently common. While my other Fn keys work as intended, I cannot adjust screen brightness with them. Pressing the buttons just does nothing and the laptop is running at full brightness at all times, even when on the battery. I have installed the latest Power Management Driver and from what I can tell, there is no version of the Power Management Software for anything newer than Windows 7. I also have installed the latest Hotkey driver (in fact, I've installed all the latest drivers for this machine.) I read in another thread that this can be caused by the latest HD Graphics driver from Intel but I actually can't even install that driver (says my system is not supported) so I am still using the latest Lenovo provided driver.
Can anyone please assist with this? I want to be able to quickly adjust screen brightness when on battery but I can't do that at present. Thanks!
Solved! Go to Solution.
07-26-2014 07:29 PM - edited 07-27-2014 12:38 PM
So I looked into this a bit more and it's actually not just the Fn keys that aren't working for brightness adjustment. I can't adjust the brightness AT ALL. The sliders are missing from Power Options and trying to adjust brightness from the Modern UI Settings charm doesn't do anything. I did some Google searches and there are a LOT of people having this problem, many of them Lenovo users. The solution for many has been to update their display driver but I have the latest release available from Lenovo and I can't install Intel's version. This is incredibly frustrating. A brand new, $1,500 laptop and it's stuck on the highest brightness setting at all times? Not good enough. Anyone had success figuring this out? Thanks!
EDIT: Just to 100% sure this wasn't the result of a piece of software I installed, I imaged my laptop and did a factory restore. Even after that, I still cannot adjust screen brightness, whether with the Fn keys or any other means. In other words, this laptop was shipped to me with this rather substantial bug in it. I have a case open with support (who had no idea what to do and said they had to look into it) but I'm hoping someone figured out a solution to this. Having full blast brightness at all times isn't acceptable.
07-27-2014 12:43 PM
I have the same problem with my L540. It started with the update of the BIOS to version 1.65. Because I didn't find a solution, I went back to BIOS version 1.64, where all the brightness options are there and work properly.
You can download older versions. When on the page with the new drivers (http://support.lenovo.com/en_US/downloads/detail.page?DocID=DS037285) go to BIOS Driver 1.65, then choose "learn more". At the end of the following page you'll see all the older versions.
That you can install version 1.64, you have to change the "Secure RollBack Prevention" Option in the BIOS: Restart the Computer. When you see the option "To interrupt normal startup, press Enter", press Enter. Press once again Enter. Press F1 to enter the BIOS Setup Utility. Choose "Security" -> then "UEFI Bios Update Option" -> then "Secure RollBack Prevention". Change this option to "Disabled". Then press F10 to save configuration changes and exit.
After restarting Windows you can install BIOS 1.64.
Another possibility is to wait for the next BIOS version ....
07-27-2014 12:50 PM - edited 07-27-2014 01:12 PM
Thank you sir! I did upgrade to BIOS 1.65 as it came out between when my laptop shipped and when it arrived. I will try this out tonight and if it works, I will inform support. Thank you again!
EDIT: I just rolled back to 1.64 and I can confirm this absolutely fixed the issue! Screen brightness now works 100% again! Thank you for the advice. I'm frankly baffled that such a glaring issue got through Lenovo QA. I will be calling support now and notifying them of this bug. Hopefully we get another update fast. Thanks again.