09-06-2016 02:48 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-and-newer-T/ThinkPad-Notebooks-Freezing-At-Boot-Up-A...
A customer-reported workaround for restoring normal boot up behavior can be found here: https://forums.lenovo.com/t5/ThinkPad-T400-T500-and-newer-T/T450-Windows-splash-freezes-after-BIOS-u...
I will post again when the BIOS update containing this fix is released for this model.
09-06-2016 06:53 PM - edited 09-06-2016 06:59 PM
I have the X1 Carbon 3 (2015) and had the same issues after updating BIOS on 18Aug as recommended by the System Update. After the update, it wouldn't start Windows 10 Pro, all hardware tests passed, reset BIOS setting, tried to recover Windows but failed (simply stalled and refused to continue)
Online chat insisted it was a software issue and had me bring it to local service centre instead of sending a tech down ( I have onsite support warranty!! )
So I brought it down and after some more testing they went ahead and replaced the motherboard but I had to wait five working days...
The tech told me "don't always update the bios - if there's nothing wrong, don't update."
Edited to confirm this bios update was bugged :/
09-06-2016 11:13 PM
In this case, there was very good reason to update because the old BIOS contained a security weakness. This makes the technician's comments somewhat inappropriate, though I realise he or she was only trying to offer reasonable advice not to enter into the risky process of upgrading firmware without good reason.
It is especially unfortunate for all involved that the new BIOS was made impossible to revert by normal means because of the security problem. The failure of the release process to identify the regression that leads to a failure to boot in some circumstances combined with the impossibility of easy reversion created a very difficult situation.
It seems that there is no need to replace motherboards, as turning off Execution Prevention in the BIOS settings appears to be sufficient to restore operation until a new BIOS is released to fix the root cause that Lenovo now understand. Disabling hardware Execution Prevention is not ideal as it lowers a safeguard against certain types of attack (especially "stack smashing"), but it is better than an unusable computer.
09-14-2016 11:06 AM
In response to customer reports that after a BIOS update to some ThinkPads, the system may fail to boot, hanging on the Windows splash screen, Lenovo has provided a Service TIP detailing a workaround. A permanent solution will be provided via future BIOS update.
The Service TIP can be found here: https://support.lenovo.com/us/en/solutions/sf16-t0079