T410 unstable screen brightness

[jaquadro]

I recieved my T410 (i5-520M, intel graphics, WGXA+ screen, 65W battery) little over a week ago and so far I'm quite pleased with the unit.  However I've noticed that when I'm on battery power, the brightness of the screen is unstable.  I'm not talking about the brightness kicking down several notches when it sits idle.  It wavers or flickers slightly, kind of like watching the 40hz refresh flicker on a CRT.  Sometimes the brightness fades in or out by up to a full notch relative to the normal brightness control, like it's being underpowered.  It happens at any battery level, but does not happen when I'm plugged in.

Are there any known causes for this kind of behavior, maybe some settings in Windows, or did I get a deffective unit?  Thanks.

[warder]

I see this too.  If you watch, it is like a dynamic brightness.  If the page is very white, it dims.  If quite dark, it brightens a little.

I believe this is not a hardware fault, but a driver issue in the display adaptor - there are actually other issues with the Intel driver too:  When powered, if the graphics card is not set to Max Performance, you also get 'delayed text paint', where it appears to slowly display text and the text almost fades into focus rather than just being solid all the time.

The Intel HD is very new - I'm sure as time goes on their will be a driver updates that fixes these subtle annoyances (which I think are actually an attempt at maximizing power savings) or provides options for them to be switched on and preferably off.

[scrybe]

I have a similarly spec'd T410 and noticed the same thing last night. When I would minimize all windows, the desktop would dim. While the stepping down in brightness wasn't extreme, it was enough to lower it about one level and each notch was noticable. On my system the entire ramping seems to take around 5 or 6 seconds.  As soon as I maximized a window it would begin stepping back up. I poked around with some settings for a bit but couldn't find any that seemed to fix it. Mine also doesn't do this when it's plugged in, only on battery power.

Hopefully this has an easy driver fix in the near future.

[cwarner]

Same thing happens on my T410. I figured it was a feature? It'd be nice to know how to disable/enable it, if so.

I also get the impression that the contrast changes itself at times.. it'll slowly change to very high, then go back down to a practical level. Anyone else notice this?

[Spearoid]

Just wanted to chime in that I too have this problem exactly as you all have described. I have been a faithful Thinkpad user for years, but am starting to really have second thoughts about my decision to get this T410. It's a beast, but with this defective keyboard and brightness issue...and the fact these newest T models are as thick as the R4x Thinkpads of the past.....makes me wonder if my loyalty has turned into stupidity.

I sincerely hope this problem can be fixed, and quickly, and I hope these panels aren't the problem.

[scrybe]

Is there anyone with a WXGA+ T410 that can confirm that this does NOT occur? I'm kind of hoping that it happens on all T410 notebooks and the few of us didn't get stuck with dud screens (and that therefore this has a software/driver fix down the road). Please make sure you're running on battery power and not on maximum screen brightness, maximize a window, wait a bit, and then minimize all windows and see if you notice a flickering to your screen brightness. If you have a chance to try this, thanks!

[procom]

Hi there,

You can try to go to Power Manager > Global Power Settings > scroll down to Dynamic Brightness Control > Uncheck all situations and see if that helps. It worked for me.

Cheers

Procom

[jaquadro]

I went and checked, but all the boxes were already unchecked.  I tried playing with other settings, switching to max battery or max performance, but either way the brightness was still unstable.

[scrybe]

Yea, the dynamic brightness control changes the brightness level depending on those checkable conditions, this is not actually changing the brightness level (the number stays the same), it just fluctuates by flickering steps.

That said, I found a way to get this to stop, at least in my case:

If you go to the Intel Graphics and Media Control Panel (right click on desktop and choose Graphics Properties...) then go to power, change the pulldown menu to 'On Battery' and change from Balance (default) to Maximum Performance, the flickering no longer happens. If you instead change to Maximum Battery Life, it still occurs.

I don't really consider this fixing it, because I feel like it shouldn't happen at any of the settings, but if it totally driving you nuts at least it takes care of it until there is some better way to handle the situation, without presumably lowering the battery run-time.

This can also be changed in the Lenovo Power Manager by going to Power Plan, expanding the system settings, and changing the Intel Graphics Power Plan to Maximum Performance when On Battery.

At first glance, my estimated battery life hasn't changed as a result, but I only recently discovered this change so we'll see. I'd still like it to go away completely at all settings.

Hope this helps...

[EDIT] Yes, I meant 'On Battery', sorry about that. I changed it above for anyone else finding their way to this problem. Thanks.

[jaquadro]

Are you sure you don't mean 'On Battery'?  Changing my Intel Graphics battery profile to maximum performance did indeed solve the flickering problem.  I find it curious however that my Plugged In profile was also initially set to balanced, but I have not experienced trouble with it when I'm plugged in.

I agree that this seems like a bug regardless.