12-18-2014 01:16 PM
I've already posted a reply and it disappeared.
Anyway, I've found a solution.
- Go to device manager and uninstall both intel and nvidia display adapters. Make sure you check "Delete the driver software..."
- Download this driver: http://support.lenovo.com/us/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t54... and execute it. It will extract its content to c:\DRIVERS\WIN\VIDEO\ . Don't install it.
- Open device manager and right-click nvidia adapter > update driver > browse my computer > let me pick .. > have disk > browse to "c:\DRIVERS\WIN\VIDEO\NVIDIA\Display.Driver\" and choose NVLT.inf > next.
- Do the same with Intel adapter and choose c:\DRIVERS\WIN\VIDEO\INTEL\Graphics\ki104067.inf
- Restart and you're done.
In the other post I've writen that I've found an older version of video drivers, but this one works too.
Thank you, cix!
Followed your steps in order and it resolved the non-functioning brightness key issue AND the eternal-sleep issue on my (brand-new, grrr) T540p as well.
06-26-2015 11:49 PM
Many thanks Cix. We use T540P's / Win7's in our office and this is a common problem. Your solution not only resolved the brightness control issue but also a known issue with the screen not recovering from sleep mode (scattered throughout this community). I had another issue where my screen actually dimmed on startup (right at the Windows fireflies) but that was caused by updating Lenovo Power Controls to the latest verstion (via Lenovo System update). Again, your fix resolved this too. I will pass this to our IT group who have had Lenovo onsite several times to no resolution.,