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What could be causing this?
Posted: Tue Dec 15, 2009 4:35 am
by Billmanweh
I've noticed lately that my T60's screen seems really dim. What is weird is that the problem seems to sort of come and go. And 'dim; doesn't exactly describe it, it's more like 'subdued'. And the little white mouse pointer is still nice and bright. And when I restart my computer, the initial windows screen is nice and bright. How odd is that? Any ideas what could be causing this??
Re: What could be causing this?
Posted: Tue Dec 15, 2009 7:06 am
by RealBlackStuff
I would say it's your LCD showing signs of aging, i.e. the CCFL is losing its strength.
Re: What could be causing this?
Posted: Tue Dec 15, 2009 8:32 am
by Billmanweh
But why would the initial windows start-up screen be bright? And the mouse pointer be bright?
Re: What could be causing this?
Posted: Tue Dec 15, 2009 9:49 am
by crazyfrog
It is not a hardware problem because I noticed the same things happened a few times on my T60p before. Normally it happens when my T60p is back from hibernation or is placed on the docking station. Reboot will make everything back to normal. I believe it is a problem caused by ATI drive not working properly.
Re: What could be causing this?
Posted: Tue Dec 15, 2009 10:09 am
by RealBlackStuff
If it is the screen, then the CCFL would burn bright when it is still cold.
As soon as the CCFL warms up, it looses brightness.
If it's a driver problem, I've never come across that... Either the driver works, or it doesn't.
Re: What could be causing this?
Posted: Tue Dec 15, 2009 11:19 am
by GomJabbar
I am not an expert on the T60, but generally speaking, on ThinkPads there is a BIOS option to dim the display when on Battery Power. Even when the display brightness is turned all the way up, it will not be as bright as on AC power with this BIOS setting (which can be changed).
Another possibility is that the power plan or display brightness level you last had the ThinkPad on is being applied after Hibernation or Suspend.
Generally a weak CCFL will begin to show a reddish tint until it warms up, or when on low brightness settings.
Re: What could be causing this?
Posted: Tue Dec 15, 2009 12:01 pm
by crazyfrog
This is definitely not a CCFL issue. As Billmanweh described, the mouse cursor was still 'nice and bright' when the screen became dim. And I would add that firsly the mouse cursor remains full brightness wherever you place it on the screen; secondly, the dim screen is in the situation between you set the screen brightness to the lowest level and a complete loss of CCFL light; thirdly, the screen still responds to Fn+Home/End keys, but the brightness ratio of mouse vs the rest of screen won't change; and finally, everything else does not seem to be affected.
If it is not a driver issue, then I would suspect ATI chip does not have correct current to drive the display after Hibernation (Suspend/sleep mode won't trigger that). But as said previously, it rarely happens (I can't remember when it happened to my T60p last time. It must be ages ago.) and reboot will bring the screen back to normal.
Re: What could be causing this?
Posted: Sun Dec 20, 2009 6:08 am
by giorgosvam
My T61 with an nvidia card and a santa rosa motherboard has also shown this exact same behaviour. The ccfl is definetely not the issue, since the mouse pointer is normaly bright.
If I am not mistaken, this only occurred when resuming on ac power, after being put in hibernation on battery with the Lenovo FullScreen Magnifier being active. However, updating drivers and (the limited) Lenovo software I use over the years did not seem to have an effect.
It only happens (very) rarely and a reboot has so far always returned the screen to normal.
George
Re: What could be causing this?
Posted: Wed Dec 23, 2009 10:29 pm
by JesseKnows
You did not say what OS you are running.
The power manager in Win7 has an option to lower brightness for some situations where the user would not be using the display much - login screen, screen saver, some others. I found that when I use this option the screen does not always resume full brightness for normal work. I disabled this option and now the screen is nice and bright.
Re: What could be causing this?
Posted: Fri Dec 25, 2009 1:02 am
by giorgosvam
In my case vista sp2 32bit. It never happened under xp (sp3, 32bit).
Power Manager cannot be causing this, it was never installed under vista. Apart from hardware drivers, the fingerprint software and the Hotkey driver are the only two Thinkvantage utilities installed. Under xp, PM is installed. Dynamic Brightness Control is deactivated.
Also, hibernating while on battery seems to be irrelevant. Just yesterday this behaviour occurred after the machine had previously been set to hinbernate while on ac power.
George
Re: What could be causing this?
Posted: Fri Dec 25, 2009 9:18 am
by GomJabbar
It seems like I read that the ATI hotkey poller sometimes causes weird problems. You might try disabling that service. You should be able to do it from Control Panel > Administrative Tools > Services.