Nov 26, 2013

Asus Transformer (TF101) bootloader fix

Playing with different ROMs or flashing funny stuff might cause your tablet to not boot correctly or always try to boot on recovery.

How to power it up?

You can try to power the tablet bypassing the bootloader with the following steps:
  1. Turn on the tablet using Vol Down + Power
  2. The tablet should display a couple of white text lines in the top, to let you know that you need to push Vol Up to enter recovery. Just wait there for it to timeout (its around 5 seconds)
  3. In the following screen, the tablet should show two icons (wipe data and android), make sure android is selected and either wait 10 seconds or hit the volume key to select it.
  4. The tablet should start normally again.
This is a workarround, so if you don't fix the problem, you will need to do all steps again every time you power up the tablet.


Whats the problem?

Most of the time, the issue is that the first string of the bootloader partition is corrupted or changed and the tablet either runs recovery or doesn't know what to run at all. To check if this is your table's issue, you need either adb or a terminal app in your device.

$ su
# cat /dev/block/mmcblk0p3
boot-recoverysadkfjl..
(more gibberish)

The solution

First of all, do this at your own risk. Second, check if the output of your boot partition has the 'boot-recovery' string, if it has any other string, this might not work at all. Now with the steps of the solution:

  1. Use either adb or a terminal/shell app with root.
    echo boot | dd of=/dev/block/mmcblk0p3 bs=1 seek=0
    
  2. Check again your boot partition, you should have something like the following
    cat /dev/block/mmcblk0p3
    boot
    recoverysadñlfj
    (more gibberish)
    
  3. Reboot
The tablet should reboot now without problem as well as it should let you enter recovery without issues.