You saved my day.

I've been suffering this annoyance since I bought the machine (X201) last year. Removing the action associated to the lid closure, then closing and opening it seems to fix the problem. Will see how consistent this workaround is (just tried it once).

For the lenovo engineers: it seems pretty evident there is a problem - for at least about a year now, across all your product line using intel graphics. Randomly, when resuming from hibernation or from sleep, the hotkeys for brightness stop working, and windows itself stops showing the brightness control in the "Windows Mobility Center" (pressing WindowsKey+X).

This is kind of random in the sense it may take any number of hibernate-wakeup cycles for the issue to show up, but in the long term it seems it always shows up. In my case, I never "shutdown", I always "hibernate" unless an update asks me to "reboot". Or unless the brightness control gets stuck as discussed in this thread (although now I expect not to need a reboot that often)

I always keep the machine fully updated with the official "System Update" packages - all along since I bought it.

X201

3249CTO

Intel graphics; Core i7, wifi b/g/n, bluetooth, webcam, no 3G, 9-cell battery

Win7 32-bits professional

Intel driver: 8.15.10.2401  (updated last week from Lenovo System Update - AFAIR)

128GB intel G2 SSD

BIOS 6QET66WW (1.36) 31/5/2011

RAM 3GB

No gaming or "out of the normal case" apps: just microsoft office & libre office, firefox 5, chrome, messenger, GIMP, skype etc

'been suffering this annoyance since September '10. To reproduce: keep hibernating and waking up the machine and eventually the issue will show up. Sometimes it will take 10 cycles or more before showing up, sometimes 2 cycles are enough. Normally the issue doesn't show up in the first cycle.

Hope we can get a real fix for this sometime. At least now we have something of a workaround.

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wrote:

Opening and closing the lid works for me too (and I also have no action assigned to lid closure).

 

 

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I'm having the same problem with a T420s and Intel graphics. Maybe 1 out of 20 times, the brightness control stops working after sleep/wake. Other hotkeys (including ThinkLight) work as expected. Adjusting brightness from the power manager does NOT work -- the brightness is really stuck.

I'll try the lid open/close lid and see if that works.

This happens consistently on my T410s, I believe since it was new over a year ago.  I can reproduce it 100% of the time by putting Win7 to sleep and closing the lid while it's still shutting down, then opening the lid and resuming after it's asleep.  After resuming into Win7, the screen is always set at the brightness it was when it went to sleep (e.g. 15 if it's been plugged in, even if it's no longer plugged in) and can't be changed unless I close the screen and re-open it (I don't have the power settings set to do anything when closing the screen, so I can walk between meetings, etc.).

Not sure if it's related, but in the same scenario, my keyboard speed also gets reset to a default speed which is somewhere in the middle of both "repeat delay" and "repeat rate", even though Win7 still shows the short/fast settings (respectively) in Keyboard Properties.  I have to move the sliders sideways, then back to the short/fast settings and hit Apply to restore the short/fast settings, or simply run the following command (I created a shortcut for it):

%windir%\system32\cmd.exe /q /c mode con rate=31 delay=0

Is there no solution for this?

I'm running:

T420s

8 GB Lenvo Supplied RAM

Latest Updates via Lenovo update

Win7 x64 ultimate

Brand new system - i can't fathom Lenovo can't reproduce this.  Have you even tried? 

What I notice is when it resumes from sleep or hibernate the display can't detect the NVIDIA one; it detects only the Intel HD Graphics drive.

Then, if I just close/open the lid, all goes back and the brightness controls then work.

I was strugling with this issue on my Lenovo Y550p since a year with no success. Now it turned out that the lid closure does help. I have the lid action set to sleep mode. Reopened it and dimmer wrks.

Very strange issue and I am very dissapointed that Lenovo is so bad in tech troubleshooting.

My T400 also has the exactly same problem. Are there any solutions?

Seems like Lenovo has no clue about their stuff:( and the issues around them. Quite sad.

what's sad is Lenovo's crap quality makes Win7 look bad - when it's the device drivers.  They sell a device, people get frustrated, and blame the wrong set of clowns.