03-23-2011 10:56 AM - last edited on 04-02-2011 02:10 AM by Agotthelf
So I've had this problem ever since I first turned on the computer coming straight out of the box from Lenovo. Everything else works fine, but every time I go from battery to AC (or vice versa) the screen immediately changes brightness according to my settings and then turns completely off for 0.5-1 second before it is on again and everything is back to normal. This happens EVERY time, so it is a permanent, 100% recreatable (and reoccuring) problem.
I've googled for a solution, but all I've found is about updating drivers and uninstalling software - all of which are not applicable on this machine. All drivers are up to date and I have none of the problematic softwares installed. Anybody knows what might be wrong or, more importantly, how to fix this?
First I thought it was an issue with having a LED screen (I have experience of only LCD screens), but this doesn't make sense to me. I would really appreciate any responses and suggestions to this annoying problem.
FYI, I'm on a X201i (3249 CTO) with Win 7 home premium 64-bit.
Moderator Note: Edited subject to match content.
Solved! Go to Solution.
03-23-2011 11:13 AM
Right click on the desktop, select graphics properties.
Select 50Hz for the refresh rate.
That should fix it. If not also try selecting "max performance" under power/power plans.
03-23-2011 11:18 AM
Thanks, but the setting is already at 50Hz... and it doesn't matter if I'm running on Max Performance or a much lower power setting. Also doesn't matter if screen brightness is at max or if it is at, say, 4.
03-23-2011 02:16 PM
May it have something to do with the black-and-white screen brightness bar shown when changing screen brightness? I just get a small peek of it, the screen dies, and then the screen turns on again as the brightness bar starts fading.
Yet I have no such problem changing screen brightness manually; when e.g. using Fn+Home or End keys. The screen only turns off when switching between battery and AC...
03-23-2011 07:08 PM
03-24-2011 03:32 AM
Does it go away if you end the 3 igfx___.exe's in Task Manager? Those three do it for me on my T400.
Thanks, ColonelONeill! There were four of those, but the answer is YES - the screen no longer turns off for a second after switching from AC to battery (and vice versa). So we have isolated and identified the problem - but what is the solution...?
03-24-2011 05:30 AM
03-24-2011 05:37 AM
The Intel control panel puts the chipset into low power mode by switching to a lower resolution and a lower power consumption mode, which seems to necessitate a screen blank.
Seems to me it was probably easier to code it that way, but I don't see why it would be *necessary*. Especially since this has been the case on none of my other and previous machines. And also since it works fine when shutting down the IGFX services.
It doesn't cause real problems, but the very slow blink (the turning off and then on) of the screen is quite annoying and takes time from work. Intel should offer a solution to this problem (or maybe Lenovo should, since all drivers go through them).