U450P brightness control (only 2 levels)

[mentosan]

Using a Lenovo Ideapad u450p and WIndows 7 32bits, controlling the display brightness does work rather unexpectedly.

Expected: Keyboard keys change the brightness, where fn+down should decrease it, and fn+up should increase it.

But, observed: The brightness alternates between very bright and very low.

the brightness levels are: 0 10 20 30 40 50 60 70 80 90 100
on my u450p the levels: 0, 20, 40, 60, 80, 100 are the same very dark, while the levels 10,30,50,70,90 are also the same very bright.

I installed windows 7 several times and the problem persists. Later I discovered that is not important to be in Windows to observe this error, I have exaclty the same in BIOS also.... Trying to modify in BIOS the brightness of the screen, I receive exaclty the same results.I supose that this problem is because of the last BIOS update (2.0.2). How can I solve this problem and where can I find the older version of the BIOS?

[Duck3]

Make sure you have re-booted, enter bios,
load default settings-> save and exit.

Then check if a backup bios file was saved by
Winplash. Maybe at folder C:\Drivers\Bios?

[mentosan]

I don't have the old version. I formated the C partition and I lost the old version of the BIOS. Where can I find it on the internet? Or can anyone upload it here?

[yigit]

try to re-install power management.

[mentosan]

Power management is a windows 7 tool. My problem is also in BIOS reflecting . that means the problem is not from windows but a little bit higher (bios driver or something form this level).

On the other side, I cannot understand why nobody else has this problem like me. I made a BIOS update and I think because of this I get the problems....Anyway for me can be helpfull to instal the old version of the BIOS but I cannot find it on the internet.

[yigit]

could be power management issue. also, check if issue persists on safe mode,too.

[mentosan]

I checked all. The problem is still there....And once again... THE PROBLEM IS ALSO IN BIOS. that means, IS NOT FROM WINDOWS or in connection with it.

[pyr0]

hello,

its an older thread, i know. but now i have the same problem after flashing new bios. i replaced the display some time ago, but everything was fine.

now, display has only 2 brigthness options. light and dark...

that is really annoying.

anybody got an older bios or some fix for it?

[pyr0]

ok i fixed it now.

removed replacement display, put in broken old one, with old it worked. put in new again, now it works also with the new one.

possible solutions:

1. only remove battery?

2. cable or connector was loose

3. some other thing

maybe this helps ya out... took me now 2 hours of try and error