Lenovo TPT brick
I have a bricked Lenovo TPT 32GB for the second time. It hangs on the static Lenovo logo. If I boot to recovery, I get a lot of errors. These problems are also common to other users.
So I did some research and found, that Lenovo uses an buggy eMMC from Samsung. The list of these can be found here: http://wiki.cyanogenmod.org/w/EMMC_Bugs
To check your eMMC-Model, boot to recovery, start ADB and follow the instruction:
# cd /sys/class/block/mmcblk0/device
# cat name
# cat manfid
The funny thing is, that Samsung released a patch for this bug- but I don't think, that Lenovo provided it.
Personally I don't think, that Lenovo will do anything about this, but if you are affected and have a locked bootloader (nvflash fails), you might find the reason for the brick.