[UNSOLVED] Asus Taichi back screen (lid) not working AGAIN after windows 8.1 update 1

It's been a while since I've had to reply to this post and as such, I would like to announce the problem is fully resolved and here is how you can fix it.

You will need to download Winflash and the latest BIOS update here - http://www.asus.com/Notebooks_Ultrabooks/ASUS_TAICHI_21/#support

Please check in BIOS before downloading the right file as to whether you have a TAICHI21 or a TAICHI21A. You can check by pressing F12 inside the BIOS screen. To reach BIOS, hit F2 repeatedly when you first turn the power on or hold Shift when you restart the computer, choose Troubleshoot, Advanced Options, UEFI Firmware Settings, and hit the Restart button.

Once you've confirmed the model number, download the latest BIOS from the support page. Extract the zip file and open Winflash on your computer. Navigate to where you extracted the zip file and select the BIOS file.

WARNING - This is considered a BIOS/Firmware update and as such, it is potentially one of the most dangerous processes that can be initiated on any device. This is one of the very few instances where you MUST update the BIOS in order to correct this problem. Please make sure that you back up any of your important data before attempting this process. When you initiate a BIOS update, make sure there are no other programs running, that this computer is connected into AC power, and that you DO NOT TURN THE POWER OFF during the process. If for any reason the BIOS update fails or if you turn off the power during the process, your computer will be unable to boot and will require that the motherboard be replaced by ASUS.

ADDITIONAL WARNING - DO NOT ATTEMPT THE BIOS UPDATE UNLESS YOU ARE IN NOTEBOOK MODE! I found out the hard way, as the BIOS update froze the entire computer. Whether or not this was a result of it being in Tablet Mode or because of Absolute's LoJack for Laptops integrating in the BIOS (all anti-theft applications do this) is beyond me. I had to have the laptop sent to ASUS and as such, the motherboard and LCD screen had to be replaced.

Once the BIOS update is complete, restart the computer. It may also be helpful for you to go back into BIOS and restore the default settings. BIOS updates can change the default settings of the motherboard and as such, your existing settings may be incorrect or improperly implemented.

Once you're back into Windows, you will need to uninstall any existing version of the Intel HD Graphics Driver/Display Audio prior to do this task. Uninstalling it enough so that it doesn't appear in Programs and Features should be sufficient enough.

From this point onward, you will need to install the latest Intel HD Graphics 4000 driver. If you would like to keep things simple, you can download the driver on the support page. However, if you're a bit more ambitious/tech-savvy, you can install the latest driver from Intel's website.

Please note that the latest driver on the Intel website will not be able to install it automatically. saying that the driver is not validated for this model of computer.  This can be circumvented by extracting the contents of the setup file into a folder (using 7-zip or another similar program) and manually installing the driver for both the Intel HD Graphics 4000 and the Intel Display Audio (may appear as High Definition Audio Device).

And there you have it - now you can put this problem to rest and if you're willing to go the extra mile, you can install the latest and greatest driver by force.

Yes, that method will restore the tablet screen to work, but you will (probably) find that your screen brightness function on the tablet doesn't work and brightness can only be adjusted on the internal screen with the top screen mirroring what you set inside and WiDi is problematic.

Best solution is to update the bios to 204 (21A model) or 208 (21 without the A suffix) and use the 3412 drivers.

This latter solution on my A model has completely restored all functionality.

I had the same problem with ASUS Taichi 21 after upgrade from 8 to 8.1

After closing the lid, the tabled display did not turn on, the only option was the special blue Taichi screen.

Now I have the tablet display working properly.

What did I do:

1. I noticed a new display driver for Taichi on the ASUS pages:

http://www.asus.com/Notebooks\_Ultrabooks/ASUS\_TAICHI\_21/#support

namely

http://dlcdnet.asus.com/pub/ASUS/nb/DriversForWin8.1/VGA/VGA\_Intel\_Win81\_64\_VER1018103412.zip

which when installed lists as:

Intel(R) HD Graphics 4000 v. 10.18.10.3412 [1/22/2014].

After this update (restarts, etc.), the tablet screen stopped working completely, even if I switched using the Taichi blue key, the tablet display did not work. Under a lamp I could see that it displayed the content of the screen but the back-light was not turned on.

2. I opened Copmoter -> Properties -> Device Manager -> Display adapters -> Intel(R) HD Graphics 4000 -> Update Driver Software -> Browse my computer for driver software -> Let me pick from a list of device drivers installed on my computer

I had the new ASUS driver from point 1) and an old ASUS driver which listed as:

Intel(R) HD Graphics 4000 v. 9.17.10.2857 [9/13/2012]

I switched to this driver (restarts, etc.) and afterwards, the tablet display started to work. After I close the lid, the tablet display turns on properly.

3. I checked windows update Win+S -> Check For Updates.

This immediately found and installed (restarts, etc.) an update to the driver which lists as:

Intel(R) HD Graphics 4000 v. 9.17.10.2963 [1/17/2013]

After this update, the close lid functionality works properly, too.

Hope this helps to the ASUS Taichi community. If you find this working, spread the word.