LG Optimus 4X HD - unlock bootloader? I have just rooted the LG Optimus 4X HD using instructions I found at How to root the LG Optimus 4X (LG-P880)?

I now need to unlock the bootloader, but for some reason the command adb reboot oem-unlock does't seem to do what it should. All it does is reboot the device, and it boots normally again. Apparently it should boot to a screen asking if I want to unlock the bootloader.

Any ideas why this is not working for me?
That was my post (actually, with the JB update, rooting got even easier) – so maybe I can help you a second time:

Initial note:

IMPORTANT: Unlocking the bootloader on the O4X only works with Firmware V20 (approved for V20A and V20B; as OP hjust upgraded using the official tools, most likely V20C works as well). To check what firmware you're on, go to Settings › About Phone › Software Information – last entry there should read "Software version", starting with "P880XXY". If XX is a 20, you're fine; if it's a 10, you'll need to upgrade your device first.

Official approach

XDA Developers has a post describing the procedure. Requirements are similar to the ones in my "rooting answer", so you should already meet them. According to that "official LG procedure", the steps are as follows:


fully charge your device to 100%
connect your phone in LG software mode (or simply enable usb-debugging)
run: adb reboot oem-unlock


Alternative approach #1

As that failed for you (and not only you, others report that as well), let's look for an alternative approach. In another thread, XDA features an unlock tool for our O4X. I just found this now when looking for a different post – and wondered about the "relock" part: AFAIK, the O4X uses FUSEs for the lock status. Once blown, there's no way back. Obviously, that XDA member found a way around that (using a boot-loader hack): "by using this program you have 16 chances to unlock relock bootloader before all fuses blown".

Alternative approach #2

That's rather a "last resort" if everything else fails: Blow all the related FUSEs directly. Again described in an XDA thread (note the original/initial post has some errors, so here's a corrected version):


open a terminal (or use adb shell)
make yourself root (run su)
get the actual FUSE state by executing cat /sys/firmware/fuse/odm_reserved &gt; /data/local/tmp/odm_reserved
in the created file, change the line 0x000000000000000000000000000000000000000000000000 00000040000000c8
write it back: cat /data/local/tmp/odm_reserved &gt; /sys/firmware/fuse/odm_reserved


While this directly blows the FUSEs, it has one advantage over the "official method": No data lost, as no factory-reset is performed – a fact it most likely shares with "alternative approach #1" ;)

Check results

Whatever approach you took: You can check the results in "Hidden Menu" (dial 3845#*880#).