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CanOfWormsFlag for United States of America

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PC shutdown randomly on Bitlocker PIN entry screen

I have 4 Asus Transformer Books running Windows 8.1. These have a TPM Chip. I have encrypted the OS drive on each of these and they all exhibit the same symptom. I am using enhanced PIN.

After powering the unit on it lands on the Bitlocker Password Entry screen. The PC will shutdown at different times, 4 seconds to 30 seconds later. It doesn't matter if AC adapter is attached or if your typing or not. I have seen other with this issue and unfortunately no answers. If I enter the Bitlocker PIN I get to the OS without an issue.

This is an Asus Transformer Book T300L, i7 with 256GB SSD.

Thanks for any help.
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McKnife
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You mean, if you hesitate and wait with entering the PIN, it shuts down? If so, it might be heat. I mean a bug that leads to overheating because at that early point, the fan control might be working incorrectly. Anyway, the problem quite surely is not with bitlocker. I would update one system's BIOS and see if that helps.
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ASKER

Thanks for the input. Yes, that is correct. Even if you begin entering the PIN it may shut down unexpectedly. I am not sure what is the cause at this point, I do lean away from it being Bitlocker however.

Another case of my symptom is this guy with his desktop PC. It shares very similar system specifications but is a desktop. I find it unlikely in his scenario it was a thermal issue wouldn't you say? http://superuser.com/questions/709642/computer-randomly-shuts-down-during-bitlocker-prompt

BIOS is up to date and the manufacturer has no beta BIOS or anything for me to go on.
You cannot say whether it is unlikely for a desktop. The thermal problems I have seen were caused by bugs in the fan control which (as I think) is part of the BIOS. In my case, even entering the BIOS (not Bitlocker even involved here) crashed after 20 seconds latest.
Please enter the bios and wait - what happens?
I just let it sit in the BIOS menu for over 10 minutes.  Fans are running when waiting on the Bitlocker PIN screen or in BIOS. Looks like Thermal is a dead end.
I don't agree completely :) Look at http://superuser.com/questions/740610/pc-overheats-when-at-bitlocker-password-prompt -> The bitlocker screen on windows 8/8.1 uses enhanced graphics (as ridicoulus as it may sound) compared to the win7 or earlier bitlocker. Your model might have problems with it. As there is no graphics driver loaded yet, we can only try and change the modern password prompt back to the classical and see if that helps. Or, better, first try what the guy in the linked thread has done if you can do the same at your bios.
Cant seem to find the method to revert to the legacy Bitlogger prompt. I assume its done with a policy change.
Ok, let me see if I can find the way to enforce the classic prompt. Meanwhile, please try what that guy had done to solve it.
Unfortunately there are no CPU or Fan settings in this VERY limited Asus Transformer Book BIOS. I appreciate your help!
Hello again.

I am sorry, I can't find how. I was sure that I once read (and saved) an article on how to do it, because it is possible. If you have a support contract with Microsoft, you might ask them. Otherwise, use the technet bitlocker forum, maybe someone over there knows how to enforce the classic prompt.
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McKnife
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Thank you for all your help on this issue. I must admit defeat as I could not figure out a solution to the Tablet shutting down during the PIN entry box for BitLocker. Instead I have purchased Symantec PGP Whole Disk Encryption and it works very well.