[Q] A few doubts about unlocking the bootloader - LG Optimus L9 P760, P765, P768, P769

Hi, I got a P765 and I was trying the adb command to unlock the bootloader
Code:
adb reboot oem-unlock
and I was presented with the following screen upon reboot
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Now I have a few doubts about unlocking the bootloader:
Is the process harmless. Of course, I understand that I will void the warranty, but is there any chance of bricking?
How long will this process actually take?
I am using the recovery by @artas182x, and I've taken a nandroid backup. Will this recovery be also erased after unlocking? If so, what should I do to restore the nandroid backup?
Is there a chance of the "Security Error" which seems to be mentioned a lot around the L9 forums to occur?
Sorry, but I'm just starting to find my way around this phone.
Thanks.

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void00 said:
Hi, I got a P765 and I was trying the adb command to unlock the bootloader
Code:
adb reboot oem-unlock
and I was presented with the following screen upon reboot
Now I have a few doubts about unlocking the bootloader:
Is the process harmless. Of course, I understand that I will void the warranty, but is there any chance of bricking?
How long will this process actually take?
I am using the recovery by @artas182x, and I've taken a nandroid backup. Will this recovery be also erased after unlocking? If so, what should I do to restore the nandroid backup?
Is there a chance of the "Security Error" which seems to be mentioned a lot around the L9 forums to occur?
Sorry, but I'm just starting to find my way around this phone.
Thanks.
Click to expand...
Click to collapse
There are two reasons for possible security error
1.You flash a custom rom or recovery, and the bootloader is still locked
2. Error while flashing with the R&D Tool
If you don't care about your warranty, unlock it so you can have a better recovery, Cyanogen & etc.
Lol, you just don't know how many people would love to be in your shoes right now.

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Thank you!!
One more doubt, do the p760 roms work with p765?
Also, could you help me with the 2nd and 3rd question in the first post.
Thanks again
Sent from LG-P765 using XDA App.

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void00 said:
Thank you!!
One more doubt, do the p760 roms work with p765?
Also, could you help me with the 2nd and 3rd question in the first post.
Thanks again
Sent from LG-P765 using XDA App.
Click to expand...
Click to collapse
Yes p760 work with p765
As soon as up press vol "up" it's done. no waiting.
Your backup will not erase. You can still use that recovery if you stay with stock, but you will need a better one if you go with a custom rom.
Do a search for TWRP in the general section Sorry it was in the Help Section, and make sure it's for P760-P768, don't use anything for P769
twrp by Lelus for your model number. Lol
I won't help you find the cwm, but you will need it to restore your stock backups created by artas182x cwm.

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Big thanks. Found CWM6 in guide in the forums. Going to try the PAC rom for P760 today

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Ok, so I tried unlocking the phone, by pressing VOL UP button at the unlock screen.
On rebot, the phone was factory reset automatically. I opened the menu using 3845#*765#
and checked the bootloader unlock option, but it says "Lock" in the pop-up messages.
Does this mean that the bootloader is not unlocked? WIll I have to do unlock bootloader
using the kdz flashing method by first flashing the p760 kdz?
Thanks

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void00 said:
Ok, so I tried unlocking the phone, by pressing VOL UP button at the unlock screen.
On rebot, the phone was factory reset automatically. I opened the menu using 3845#*765#
and checked the bootloader unlock option, but it says "Lock" in the pop-up messages.
Does this mean that the bootloader is not unlocked? WIll I have to do unlock bootloader
using the kdz flashing method by first flashing the p760 kdz?
Thanks
Click to expand...
Click to collapse
I never heard of it performing a factor reset, but I looked closer at your pic and I see, that's what it said was going to do. The easiest way to check, is put your phone in the s/w upgrade mode. That hidden menu doesn't give out the correct information on every kdz. Flash the 20B euro kdz, it "should" give out the correct information. By the way, what kdz did you use?
CM 10.1 P769

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I never used any kdz, I tried it on my stock jb v20b firmware. Should I flash 760 kdz?
Thanks
Sent from my LG-P765 using xda app-developers app

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void00 said:
I never used any kdz, I tried it on my stock jb v20b firmware. Should I flash 760 kdz?
Thanks
Sent from my LG-P765 using xda app-developers app
Click to expand...
Click to collapse
Just check by putting you're phone in s/w upgrade mode. Turn off phone, hold vol + and enter the USB cable into your PC. If unlocked, it will state "bootloader unlocked" while in the s/w mode.
CM 10.1 P769

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void00 said:
Ok, so I tried unlocking the phone, by pressing VOL UP button at the unlock screen.
On rebot, the phone was factory reset automatically. I opened the menu using 3845#*765#
and checked the bootloader unlock option, but it says "Lock" in the pop-up messages.
Does this mean that the bootloader is not unlocked? WIll I have to do unlock bootloader
using the kdz flashing method by first flashing the p760 kdz?
Thanks
Click to expand...
Click to collapse
Check your PM. I have send you the detailed guide for rooting LG L9 P765 to the best of my knowledge. The guide is very simple to follow so Happy rooting & enjoy. Disclaimer: Do it on your own risk. If it helps do not forget to hit :good:thanks button.

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kuma82 said:
Just check by putting you're phone in s/w upgrade mode. Turn off phone, hold vol + and enter the USB cable into your PC. If unlocked, it will state "bootloader unlocked" while in the s/w mode.
CM 10.1 P769
Click to expand...
Click to collapse
I tried this and it said Bootloader:Unlocked
Thankyou!!
So, now i can go and flash roms through recovery right.
@Snow Panda, i tried the exact same method. Though i'm using ubuntu and not windows. I had already rooted using the LGPwn app and installed @artas cwm recovery before trying to unlock the bootloader. Thanks for the guide btw.
Sent from my LG-P765 using xda app-developers app

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You are all set my friend. Now get a better recovery. Look up my last three (or 4) post on this thread
http://forum.xda-developers.com/showthread.php?p=36620368
Sent from my LG-P769 using xda app-developers app

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kuma82 said:
You are all set my friend. Now get a better recovery. Look up my last three (or 4) post on this thread
http://forum.xda-developers.com/showthread.php?p=36620368
Sent from my LG-P769 using xda app-developers app
Click to expand...
Click to collapse
Thanks, you told me to check twrp recovery before.
But I can only find TWRP for p760. Will this be compatible?

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void00 said:
Thanks, you told me to check twrp recovery before.
But I can only find TWRP for p760. Will this be compatible?
Click to expand...
Click to collapse
P760 and P765 are 100% compatible
Sent from my LG-P769 using xda app-developers app

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kuma82 said:
P760 and P765 are 100% compatible
Sent from my LG-P769 using xda app-developers app
Click to expand...
Click to collapse
So I flashed twrp recovery (from here: http://forum.xda-developers.com/showpost.php?p=43032385&postcount=7 )
using the fastboot method.
Here's the screenshot of what I did
After reboot, when the led's were blinking, I pressed Vol Down, but it entered the CWM recovery which I had before.
Shouldn't this recovery be overwritten?
UPDATE: I also tried adb reboot-bootloader and the phone just restarted as normal
Thanks

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Sorry, I didn't give you the key combination. Hold volume (-), home & power (let go of power when the the lg logo comes up)
Sent from my LG-P769 using xda app-developers app

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kuma82 said:
Sorry, I didn't give you the key combination. Hold volume (+), home & power (let go of power when the the lg logo comes up)
Sent from my LG-P769 using xda app-developers app
Click to expand...
Click to collapse
Thanks! Booted in to TWRP recovery. I did a backup.
Going to flash a rom and see if everything will go alright.

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void00 said:
Thanks! Booted in to TWRP recovery. I did a backup.
Going to flash a rom and see if everything will go alright.
Click to expand...
Click to collapse
Enjoy custom ROMs
If installing the twrp didn't give you security error, nothing will
Sent from my LG-P769 using xda app-developers app

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kuma82 said:
Enjoy custom ROMs
If installing the twrp didn't give you security error, nothing will
Sent from my LG-P769 using xda app-developers app
Click to expand...
Click to collapse
Thanks a lot for your guide and help

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Snow Panda said:
Check your PM. I have send you the detailed guide for rooting LG L9 P765 to the best of my knowledge. The guide is very simple to follow so Happy rooting & enjoy. Disclaimer: Do it on your own risk. If it helps do not forget to hit :good:thanks button.
Click to expand...
Click to collapse
Sir can you send that detailed guide to me please? I need it too.