Adaptive Brightness not working after BIOS update

[KostadinS]

After updating the System BIOS to version F.28 on a Spectre X360 14-ea1xxx the Adaptive Brightness and Adaptive Contrast options in Settings--System--Display are missing on Windows 11.

I think that this version completely breaks the sensor for ambient light. I tried this in both Windows 11 and Linux so it's not an OS problem. The sensor in Linux is not detected at all. It was previously working fine with Version F.27.

[anaymakan]

can confirm the adaptive auto brightness has disappeared for me after the update to F28 on a Spectre x360 14 i5 11th gen running Windows 10. Has to be a BIOS issue as it was working fine yesterday on F27 but the moment I updated I noticed the issue. Not really fussed as my brightness doesn't really change but strange at the same time. 

[KostadinS]

I did a bit of digging and probably the root cause is this firmware update from Intel: https://support.hp.com/us-en/document/ish_7678863-7678903-16/hpsbhf03833 for the sensors hub.

There is probably some incompatibility with the sensor on the HP Spectre x360. What I don't know is how can we report this bug to HP.

For me it's really annoying as I used the auto brightness all the time.

[blk64]

Same issue for me, F.28 bios update killed adaptative brightness.

Model 14-ea0000sf

I tried to rollback in so many ways to version F.27 but none succeded.

Errors are "Unable to open bios image file" or something like "invalid signature/bios file"

I tried recovery with Win+B, through HP PC Hardware Diags UEFI menu, even with USB recovery key made from another computer...

Is there a way to rollback?

@HP : can you correct the bios re-enabling adaptative brightness and publish a new bios version please ?

[blk64]

Yesterday, I got a phone call to HP Support

TL;DR: adaptive brightness still not working...

Tech I talked to asked me to:

load setup defaults

CMOS Reset with Win+V

Checked drivers, stated "it's ok"

Asked me to try to update my Win10 Enterprise LTSC

And finally, asked me to reinstall Windows...

Windows resintall has been done with ISO media, drivers have been installed by Windows itself during first run of system updates, GPU driver is in last available version (the one that ends with .3790)

[blk64]

Antoher phone call with HP Support

Tech: "maybe it is an hardware issue, you may send us your laptop for diagnostic."

Me: "No it's firmware issue. Intel and HP should work together on BIOS F.29, a new version that correct SA-00721 and restore adaptive brightness"

Tech: "Did you resintall your Win enterprise?"

Me: "yes, but if you ask me, I can try another reinstall with latest Win11 Home"

Tech: "yes let's go for Win11 Home, i'll call you back in days"

[KostadinS]

This is definitely a firmware issue. I had no issues before the update. Now multiple operating systems fail to recognize the sensor. Good that at least HP are aware of the problem. Hopefully they work on a fix.

[blk64]

another phone call today

HP Support tech : "not our fault. Rollback to F.27 not possible. Want your adaptative brightness back? pay!"

Me : "aller vas-y laisse tomber"

Usefull info for all people who have lost adaptative brightness:

https://support.hp.com/us-en/drivers/selfservice/swdetails/hp-spectre-x360-14-convertible-pc-14-ea0000/35698516/swItemId/ob-309618-1

Bios F.29 is here, but I don't want to loose something else!

Anyone to test this new version?

[anaymakan]

Just updated to F29 and adaptive brightness is still missing. In the patch notes, it basically just mentioned security updates. 

[KostadinS]

Not their fault? So who is responsible for making sure the BIOS updates work?

Regardless I just tried F.29 and it makes no difference to the adaptive brightness issue. It doesn't seem to break anything else though.