06-08-2018, 02:43 PM
Hi,
I am trying to solve the problem with Lenovo Yoga 700 14isk BIOS update. It was accidentally flashed to a newest firmware but without Bitlocker suspending. After that, OS found BIOS version change and wants recovery keys instead of taking it from TPM module. Unfortunately a pendrive with restore keys was lost, so the only chance is to downgrade the BIOS. It's based on Phoenix.
I run the OS from external HDD and tried to downgrade it, but it shows warning that downgrade will cause TPM module clear. This notebook has Intel PTT enabled, so the decryption keys are wrote somewhere at Intel's chip.
The status of TPM module shows that it's owned by other system, so definitively it wasn't cleared.
[attachment=14463]
I created bootable DOS usb, but I didn't try to flash it by DOS tool, because I am not sure which options should be marked.
I am attaching unpacked BIOS images (newest and previous) in CAP container with dedicated flash tools.
https://1drv.ms/f/s!AhSrYdRl4bnajUJl1KsXDmq_goKS
Bitlocker checks hardware changes during boot process. If I could recover the previous state it should let me in.
I think that Windows during booting with Bitlocker checks only Bios version or maybe checksum.
I spent a few days trying to find a solution, but I got nothing. So maybe someone from this forum could help me?
Any ideas how to flash it without TPM clear?
Thanks for help!
I am trying to solve the problem with Lenovo Yoga 700 14isk BIOS update. It was accidentally flashed to a newest firmware but without Bitlocker suspending. After that, OS found BIOS version change and wants recovery keys instead of taking it from TPM module. Unfortunately a pendrive with restore keys was lost, so the only chance is to downgrade the BIOS. It's based on Phoenix.
I run the OS from external HDD and tried to downgrade it, but it shows warning that downgrade will cause TPM module clear. This notebook has Intel PTT enabled, so the decryption keys are wrote somewhere at Intel's chip.
The status of TPM module shows that it's owned by other system, so definitively it wasn't cleared.
[attachment=14463]
I created bootable DOS usb, but I didn't try to flash it by DOS tool, because I am not sure which options should be marked.
I am attaching unpacked BIOS images (newest and previous) in CAP container with dedicated flash tools.
https://1drv.ms/f/s!AhSrYdRl4bnajUJl1KsXDmq_goKS
Bitlocker checks hardware changes during boot process. If I could recover the previous state it should let me in.
I think that Windows during booting with Bitlocker checks only Bios version or maybe checksum.
I spent a few days trying to find a solution, but I got nothing. So maybe someone from this forum could help me?
Any ideas how to flash it without TPM clear?
Thanks for help!