W500 screen brightness issue

[TwigletZone]

First off; Happy Easter All!.

The problem I'm hoping some of you kind and knowledgable folks can help with is; I have recently aquired a W500, it seems quite a nice system, has a nice new keyboard and ans is quite clean, but...... the screen is a 1680x1050 unit and works fine EXCEPT for one rather anoying issue; I can't adjust the backlight brightness at all, not with the "Fn + brightness up/down" keys or in software, it is just stuck at full brightness! Any one know where to begin with this issue please? Tah....

The system has the latest Lenovo BIOS and behaves the same under Win10 and Win7 (Dual Boot). It has been dismantled/refurbished by previous owners by the look of some things, which makes me think the display may have been replaced at some point in it's life, its not a new-new unit as it has some wear marks on it.

I did try to take the lid covers off to see details of the the display but for the life of me I can't work out how to get the lid cover off after the beazle is removed, it seems to be stuck in the bottom left corner, it's definatley doesn't seem as easy as taking a R61 apart!

Any help would be appreciated, thanks

[RealBlackStuff]

The bottom right/left bezel corners are held there with a screw.
You need to remove the screw-cover first.
Also, have you looked in the T500/W500 manual? See HMM-link above.

[TwigletZone]

Hi,

Thanks for your reply.

Yes I can get the beazle off no problem, it's the actual lid top or display cover, (what ever it's called), that I can't seem to separate from the display frame. I have even removed ALL the visible screws behind the beazle, including the hinge screws which leave the whole assemle riskily flapping about, but the lid/cover stubbornly remains attached!

Any clue as to the display stuck at full brightness? thats the main issu here, anything I need to check? tah

[as.nielo]

Have you tried this key combo fn+brightnessUP/DOWN during startup or in BIOS? If it won’t work in BIOS then it is a hardware issue definitely. If negative then I’d say it’s ACPI or thinkpad buttons driver problem that you can fix by installing the right driver.

BTW this device isn’t meant to work with win10. You may expect some weird errors with CMOS after several times it hibernated or restarted. I use w700 (same series but larger screen) and have decided to ditch win10 completely.

[TPFanatic]

I have never been able to get T/W500 to change brightness in BIOS.
In OS it is controlled by the graphics driver. All W500 have ATI GPU / Switchable Graphics so make sure you get the correct driver for it. Or you can go into BIOS, Power, Display and set to Integrated only (disables ATI) and disable OS Detection so it sticks, then just use the cooler-running Intel graphics and you don't have to worry about Switchable Graphics which is not supported in Windows 10.

[TwigletZone]

Hi,

Thanks for the replies peeps,

I have tried "Fn + brightness up/down" in BIOS, nothing happens and its at full brightness while in BIOS to. I have installed ATI, Intel and switchable (Which does both) drivers from Lenovo's support site, W7 is fully updated aswell. (As a side note, I use W7 as my main, W10 is there just cause it came with it and I expect it won't work well on a ten year old machine!) I am suspecting some sort of hardware issue the more I think about it; wrong screen type possibly?

I have also tried just descrete graphics only and swichable in BIOS, I've not tried just Intel only, as to be honest is should work with what ever is selected! It's currently as switchable, using ATI. The screen brightness wont change under software either, for example Windows Power settings, but the brightness slider DOES change with the "Fn + brightness Up/Down" keys, but the screen does not change!..... Its a real mystery!

[TPFanatic]

Are the power management drivers up to date?

Another troubleshooting tip you can try is with a Linux live CD or Ubuntu install preview, they tend to just work OOTB with ThinkPad features and it'd be interesting to see if the brightness control works there.

[Droider]

Hi,

Is there any chance that the display had been replaced with some compatible one before ? This usually happens when an unsupported display is used.

[TwigletZone]

Are the power management drivers up to date?

Yep, all drivers from Lenovo's web site and Win7 all fully up to date

Another troubleshooting tip you can try is with a Linux live CD or Ubuntu install preview, they tend to just work OOTB with ThinkPad features and it'd be interesting to see if the brightness control works there.

Good Idea! I tried both Knoppix and a RedHat live CD, both do as windows does, sotware adjusters/sliders move, (and stay between boots and distros), but screen stubbornly stays at full brightness.

Hi,

Is there any chance that the display had been replaced with some compatible one before ? This usually happens when an unsupported display is used.

This is looking highly likely! And was the reason I wanted to remove the lid cover to read the info from the LCD so I could post it, as you rather clever chaps hopefully could point me at a list of what part numbers or LCD types are fully compatable with the laptop. This laptop definitley has been repaired/refurbished at some point in its life as there are signs of tapering! (missing screws underneath, missing screw covers on beazle, ect).....

Is there a "whitelist removed" BIOS for this system? (BIOS is up to date, V3.23), Tah

[RealBlackStuff]

No LCD whitelist, but look for a WUXGA Sharp lq154m1lw2a / lq154m1lw02.
I have recommended these here dozens of times.

We still don't know which screen you have and if it's LED or CCFL.
It could be a bad (LED) subcard or bad (CCFL) inverter.
Maybe try dis-/re-connect the LCD-cable (with all power/batteries removed)?

[TPFanatic]

You can run Entech monitor asset manager / moninfo to get your screen information from OS. https://www.entechtaiwan.com/util/moninfo.shtm
Very handy software, I love it. Do post back the LCD model if you run it.

I was also thinking it could be a faulty inverter not letting the CCFL step down.

[TwigletZone]

You can run Entech monitor asset manager / moninfo to get your screen information from OS. https://www.entechtaiwan.com/util/moninfo.shtm
Very handy software, I love it. Do post back the LCD model if you run it.

Nice! That is handy little piece of software, thats now added to collection Windows Utils! Thank you

Results;

Manufacturer............. Lenovo
Plug and Play ID......... LEN4053
Data string.............. LTN154P3-L02
Serial number............ n/a
Manufacture date......... 2007, ISO week 0
Filter driver............ None
-------------------------
EDID revision............ 1.3
Input signal type........ Digital
Color bit depth.......... Undefined
Display type............. RGB color
Screen size.............. 330 x 210 mm (15.4 in)
Power management......... Standby, Suspend, Active off/sleep
Extension blocs.......... None
-------------------------
DDC/CI................... Not supported

Odd manufacture date as the machines date is 10/04

I can't get to the panels plug as I can't fully remove the back cover/lid, but I can get to the inverter as it's just behind the beazle. I havn't opened the laptop body up yet, but I will at some point to clean the heatsink and refresh the thermal paste, so Ill check the connection there to when I do that.

Tah for you help so far I'll post back when I've re-seated the cables I can get to.

[TwigletZone]

Another question or two;

Would an inverter from a R61 work? I have one I could pull out and try. And is the a difference between the 1280x800 and 1680x1050 inverters? I might also have a workin 1680x1050 display panel aswell from a R61 I could pull out and reuse if compatable.

[TPFanatic]

For removing the back cover, which is thin plastic, you kind of reach around the edges and pry it away from the magnesium. Don't worry about it flexing.

[RealBlackStuff]

That is a Samsung CCFL screen with an inverter.
R61 inverters will not work, but any of these T60 ones will work:
42T0078 / 42T0079 made by Hitachi, also has marking INVC753
41W1012 / 39T5658 made by Hitachi, also has marking INVC753
13R1014 / 13R1015 made by Sumida
Those inverters would also work with the above mentioned Sharp WUXGA (which has CCFL).