[SOLVED] Lenovo T420 & Nvidia NVS 4200M - Win10 Brightness problem... pfffffff

[Zucca]

 

Lenovo T420 here with NVIDIA NVS 4200M. Upgraded to Win10... "holy crap everything works"... emmm I used last week for the first time running on batteries (no AC power)... well I found out can´t adjust the brightness anymore...

oh... the win10 driver is faulty...
Now I have a Laptop which drains the battery as fast as possible, and I need sunglasses to not get my eyes watering in the dark....

A big thanks to all the Win10 and Nvidia Intel GPU technical team for the very professional job. How can you guys have done such a beautiful mistake? 

Already following the rabbit in the googling hole to find out how to fix this mess.

A voice inside me is keeping bugging me:"I told you not to update..."

Thanks EEVBlog, I feel better now.

[AntiProtonBoy]

Couple of things:

1. If you only upgraded and not installed Windows 10 from a clean slate, you are more likely to have a million and one things go wrong.

2. Many drivers are usually written by a third party, generally by the hardware vendor, so MS might not be at fault here.

[AntiProtonBoy]

Oh yeah, and:

3. Update all your Win10 drivers.

[wraper]

You should as minimum reinstall to the new versions both Nvidia and Intel GPU drivers (download from their websites). And better do a clean install in the first place if don't want it working like shite.

A big thanks to all the Win10 and Nvidia Technical Team

Nvidia is certainly not at fault in this case, display is connected to the integrated Intel GPU. Image from Nvidia (when it is active) is displayed through the Intel GPU.

[Zucca]

nstalled Windows 10 from a clean slate

did that.

Update all your Win10 drivers.

When I let windows search for new driver it returns everything is up to date.

Try getting the required driver from the Nvidia website.

Did that no hope.

Intel GPU drivers (download from their websites)....

That could help, will try it.

..is displayed through the Intel GPU.

OP corrected!

I'm at work now, will post details later. Thanks guys you are fantastic.

[wraper]

When I let windows search for new driver it returns everything is up to date.

[Zucca]

 LOL sorry I deserved that. I just told you what I did so far. I will dig deeper soon...

[AntiProtonBoy]

When I let windows search for new driver it returns everything is up to date.

You should fetch drivers directly from the chipset vendor, starting with Intel Chipset Device Software as it manages pretty much half the functionality of your machine, particularly power management, and so forth.

[wraper]

Try getting the required driver from the Nvidia website.

Did that no hope.

64 bit version: http://www.nvidia.com/download/driverResults.aspx/109629/en-us

[Zucca]

Intel Chipset Device Software as it manages pretty much half the functionality of your machine, particularly power management, and so forth.

99% think I did that, if not yes I am stupid. 

http://www.nvidia.com/download/driverResults.aspx/109629/en-us[/url]

oh yeah... was there, did that.

Interesting I try to adjust the brightnees in the win power option and also fron the special key on the keyboard...  nothing happens, or better when I use the special key I see the little cursor overlay moving but nothing changes,

If I am inspired I will do a video on YT, maybe measuring the mA drained from the battery  .

[Zucca]

All right,

Got the NVIDIA Driver updated again



I also installed the Intel chipset as suggested...

And... it is not working. Interesting enough I found a this:

http://support.lenovo.com/de/en/downloads/ds029026

which gave some of the hotkey functions back (I wrote the OP in this situation, just telling you now this)... even if win 10 was not listed... bah...

and this:

http://support.lenovo.com/de/en/downloads/ds000774

seems to do nothing...

I think I'min the same situation of this guy:



only problem I can't roll back to the right driver....

What a mess..

Also I tried the method two of this:

https://support.lenovo.com/de/en/documents/ht079345

did not help.

[wraper]

I also installed the Intel chipset as suggested...

Chipset driver is not required for this to work. You need to install Intel graphics driver.

[rrinker]

 Friend had some odd errors popping up on her Acer laptop after Windows 10 - seems some of the crapware Acer preinstalled on it doesn't work with Win10. I also was unable to uninstall it - the uninstall would fail because some services wouldn't run in Win 10. I ended up going to the registry to find out where this software lived and just deleted the file and any reference to it. No more errors.

 I'm kind of glad I got a new SSD and did a clean install of 8.1 on my laptop before the 10 upgrade, that way I had none of the HP crapware, just standard Windows stuff with all the Intel chipset drivers and nothing else - the upgrade of this machine to 10 was completely smooth as a result.

[wraper]

BTW have you opened device manager to check if all devices are functioning?

[senso]

Neither GPU as a word to say about display brightness, its a PWM generated by the SuperIO/EC...
So, update your BIOS to the latest available, grab the latest chipset and Intel ME drivers, then go to the Lenovo site and grab the IO/ACPI/ATK drivers and install them..
Its like blaming the WiFi card as the culprit for lack of sound..

[wraper]

Neither GPU as a word to say about display brightness

Though intel GPU driver somehow has automatic brightness control built in. And GPU driver usually is essential for brightness control to work.

[Monkeh]

When I let windows search for new driver it returns everything is up to date.

You should fetch drivers directly from the chipset vendor, starting with Intel Chipset Device Software as it manages pretty much half the functionality of your machine, particularly power management, and so forth.

You know all that does is name things in the device manager, right?

[Zucca]

BTW have you opened device manager to check if all devices are functioning?

yees

https://support.lenovo.com/de/en/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t420/solutions/HT103535#/lenovonotebook

so it looks like my device is not supported for Win10. Game over?

Trying now to upgrade the BIOS... hope not to brick the machine.

[wraper]

Game over?

Not listed as supported does not mean anything.

[wraper]

BTW have you opened device manager to check if all devices are functioning?

yees

Are both Nvidia and Intel GPU names displayed correctly and not like something generic?

[Zucca]

update your BIOS

Updated to 1.49, and selected "NVIDIA OPTIMUS" in the BIOS menu...

http://support.lenovo.com/de/en/downloads/ds018785

and boom now it works.... 

Let's measure the current now and wait for the next issue to solve.

mmmm I attached some wire to the + and - battery inputs on the PC... turned on the PC with 10.8V on those ones and it was draining 2.5A-2A... then I got a warning message "critical battery power" and game over (I think it is missing the other battery connections). I tried then to connect something on the DC input from the laptop charger... too difficult.... So since I don´t want to open the unit just for the sake of measuring the current, I pass. Thanks.

[senso]

Neither GPU as a word to say about display brightness

Though intel GPU driver somehow has automatic brightness control built in. And GPU driver usually is essential for brightness control to work.

But its via the chipset that talks to the superIO(in most cases via a PS/2 interface that then does the magic, sometimes you just need the right mix of drivers, sadly most people dont install their drivers and then complain(not talking about OP!), and the BIOS is always a culprit, crappy ACPI tables and the cluster fuck that is UEFI bios variables and Windows poking them like no tomorrow..
At least its working now!

[AntiProtonBoy]

You know all that does is name things in the device manager, right?

It's a lot more than that. Also allows Windows to discover correct chipset drivers more reliably.

[Monkeh]

You know all that does is name things in the device manager, right?

It's a lot more than that. Also allows Windows to discover correct chipset drivers more reliably.

Even Intel themselves say just about all it does is supply names. There's really no drivers under that umbrella that Windows needs help finding.

[Zucca]

Updated to 1.49, and selected "NVIDIA OPTIMUS" in the BIOS menu...

well it turns out that "NVIDIA Optimus" is not the right one for win 10 (got driver problems), please choose Discrete graphics.