09-06-2016 02:45 PM
In response to customer reports of ThinkPad notebook systems freezing after upgrading to a BIOS published in August 2016, Lenovo has investigated and found root cause.
More information can be found in this KB article: https://forums.lenovo.com/t5/ThinkPad-T400-T500-an
A customer-reported workaround for restoring normal boot up behavior can be found here: https://forums.lenovo.com/t5/ThinkPad-T400-T500-an
I will post again when the BIOS update containing this fix is released for this model.
09-06-2016 04:11 PM
Regarding the KB article..
> This is known to occur on ThinkPad systems running Windows 7 and Windows 10 installed via legacy Windows 7.
Our Windows 10 was preinstalled on both computers by Lenovo.
> Root cause was identified as a conflict between the BIOS and a feature in ThinkPad Power Manager for Dynamic Brightness Control. This setting is disabled by default, so only customers who enabled the feature would encounter this issue.
We never touched it.
09-09-2016 12:40 PM
ITs happening as well on the W541's after upgrading to BIOS V2.28. I disabled execution prevention in BIOS for Temp fix....waiting for an update for W541
09-11-2016 11:08 AM
I'd like to report that it seems to affect certain X type laptops as well:
Currently my laptop at least booted the Windows Auto repair, so it seems it's now my turn to wait those 20 mins.
What I find rather strange is that I could also not boot any linux system (Ubuntu 16.04 and Sabayon linux).
I don't understand how this can relate to the dynamic brightness control and affect my linuxes.
09-12-2016 02:44 AM - edited 09-12-2016 03:34 AM
EDIT 2: Fixed! Can now boot normally. I had to change 'Security Chip' to either Inactive or Disabled. Execution Prevention could be set as Enabled and work.
EDIT: As I replied in the X forum, I am a X1 Carbon user with the BSOD after the BIOS update, and disabling EP has NOT fixed my issue. I am running Win 7 Pro and it BSODs every time it gets to the loading Windows screen, whether it be for booting or repair after the 'Windows is loading files' screen. Getting pretty worried over here.
10-02-2016 05:37 PM
Just want to check back in, found out that v1.26 has been posted to the support page on September 29th.
The changelog immediately looked good, as it mentions:
- Fixed system may hang windows splash logo after update BIOS v1.25.
The flash went without any problems and has fixed the issue for me!
Download the update here.
Hope it works out for everybody else too! Appreciate the help pushing this Amy.