[LG Optimus L9 P760, P765, P768, P769] cmahendra:
FAQ: Frequently Asked Questions (SEE ALL THREE POSTS)

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Q) I have somehow soft-bricked my L9 which was on Jelly Bean and now I cannot go to SW Upgrade Mode.

A) Based on this workaround I have modified few words (for better understanding) to start phone in SW Upgrade Mode.

Download LG Mobile Support Tool and do the following steps:

..1. Remove the battery and the USB cable from phone.

..2. Without the battery, plug the USB cable and connect the PC to the phone with USB cable.

..3. Press and hold (VolumeUp) key and press (Power) key for 2/3 secs. You should see "S/W Upgrade" on the screen after a few seconds.

..4. Re-insert the battery in the phone.

..5. Start LG Mobile Support Tool(B2CAppSetup.exe), let it find the phone (and load drivers) and start the software update.

IMP: This method is online Software upgrade mode and faster internet will be required which will download around 500+mb file while recovering. So be prepared pals.

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Q) Can I flash roms (kdz files) released for P765/P760 on my P768/P769?

A) No! The hardware of these variants are different than each other and you should not just flash any rom on any variant. The compatible list is as folows.

P760 can be safely flashed with P760 and P765 only.

P765 can be safely flashed with P760 and P765 only.

(Both above variants are compatible with each other, except only NFC feature, which is a minor change and does not harm cross-flashing. Do not flash P768/769 on these two. They will brick phone.)

P769 can be safely flashed only with P769 roms.

P768 can be safely flashed only with P768 roms.

Do not flash any other roms except the original ones.

Warning P769: If you flash P760/7655 rom on P769, then screen will break/wonky/mirrored and will be very hard to recover for a noob)

Warning P768: If you flash P760/765 rom on P768, then camera will break-down and this is also hard to recover.

New pals are advised that, before flashing any rom for first few times, keep asking in this thread or any other related thread. Just within few minutes you will get reply from many helpful pals.

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Q)

Even after fresh flashing or when any experiment goes bad, you may see following DEAD ANDROID with Red Triangle and exclamation mark over its body. What to do?

Workaround A) You may think, you have just killed it, but HEY, Wait, Relax. Even I got this issue when I flashed Prada Apk for CWM and then reflashed.

FORCE SWITCH OFF: First press Power Button for 10 seconds, phone will turn off, like laptops turn off with same trick. Then restart phone and see if it starts normally. If no then you need to do hard reset as mentioned below.

HARD RESET: Remove the Battery and insert it after few seconds. And now do the 3 button HARD RESET. First press VOLUMEDOWN and HOMEbutton. Then Press Power button only for 3 seconds and release power button but dont release VolDown and Home button and KEEP BOTH PRESSING until you see a Bigger Green Standing Android and circulating Molecular structure above it. DONE! Your Android should boot now and will be back in action. ALL DATA AND APPS WILL BE WIPED, BUT HEY IT GETS ITS LIFE BACK and LIFE'S GOOD. :D

Workaround B) You might have issue with bootloader or CWM installation error, JUST FLASH KDZ AFRESH and you will again see above screen after finishing, Just Repeat Workaround A, hard-reset it immediately. (I had to do this at least thrice, and everytime it came back ) Thats why they call it, LG DEVICES ARE UNBRICKABLE.:D A completely ignored feature which wins above all.

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Q)

What is KDZ? Sorry I am first time on XDA with new LG Phone.

A) Welcome to XDA, Like we install Windows XP or 7 on pc, every phone needs Operating System too to function. Phones also need this OS and its Drivers to be installed and functioning. The OS files here are generally called "FIRMWARE" or "ROM" files. The company LG bundles whole OS, Drivers and other supporting files and applications, into one single huge file and they gave it a file-extension name as "KDZ". The regular updates of OS are also released by manufacturers either via download or directly in device via 3G or WiFi which is also called FOTA (Firmware Over The Air). Here in this thread we are talking about flashing (clean install) of the KDZ on phone, which should actually be done by LG Service Centres only and not us. :D But well these days everyone is doing that with the help of helpful tips and apps given by experts on XDA. Hope some things are clear here. :)

Size of KDZ file: Generally KDZ files for LG L9 are around 480+MB to 600MB for ICS version. For Optimus 2x the KDZ file is around 300MB (GB) to 600MB (ICS). Hope this helps too. :)

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Q)

Well, I could successfully Root my phone, but how to install CWM?

A) Working CWM 6.x by Artas182x is here. Read instructions carefully.

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Q)

After installing CWM by Artas182x, how to go Recovery Mode (in CWM menu)? Could not go by pressing Power button while pressing VolumeDown.

(Why LEDS on phone blink rapidly while rebooting phone?)

A) That method is wrong for CWM. The correct method is Switch On phone with single power button and release it. When LG logo appears in a moment LEDS start blinking, quickly press and release VolDown button, you will be now in CWM menu.

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Q)

After Rooting on V10C, can I update to latest ROM, keeping device ROOTed?

A) Not directly by upgrading via OTA (Air). BUT YES at some extent you can do it for some models. There is a thread by me with Collection of Rooted CWM Backups for various models. Read thread carefully for details. While writing this (on 24-Feb) I am on Rooted P765V10G due to the CWM Backup sent by another user DarkFable.

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Q)

How to start L9 phone in SW Upgrade Mode and connect to PC?

A) Connect USB cable to PC but do not connect to Phone. If phone is on, Switch it OFF. While Pressing VolumeUP button and insert USB cable into phone and keep pressing the button, let windows load any drivers (if required), wait until it finishes. Phone will show SW Upgrade Mode screen (SEE IMAGE) and you can release the button.

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Q)

I am not able to Root my P765/P768/P769/P760? What could be wrong?

A) Everything to ROOT L9 is available in this thread, read carefully and do as instructed.

This tutorial was made after successful and easy flashing of India V10C Rom and Rooting P765 on it. You can find download link from second post above for matching V10A for your variant. You can download and flash roms released for other countries too, as most of them will have English (US) as a common language.

A user could Root P760V10A and using Voodoo, updated to [V10E on OTA] and Restored Root with V10E. Will not work with offline flash method.

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Q)

Can we OverClock L9?

A) I have not tried but yes, someone already did OVERCLOCKED L9 to 1.3GHz here. http://xdaforums.com/showthread.php?p=34192656

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Q)

Where can I find official KDZ ROM for flashing for my device?

A) You can visit my OFFICIAL ROM LINKER page , enter your IMEI and find your own latest ROM available to Download. Works for any LG Android SmartPhone. Or you can visit this page for old Official KDZ for any device any country.

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Q)

What if I HARDBRICK my phone and it never recover back?

A) According to this post, one of our L9 expert artas182x who says, "For now our L9 is unbrickable, because we haven't got access to recovery.img and boot.img and we can try many methods to port CM9 or CM10 without hard brick." And that is fact, so lets relax at the moment. :D

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Q)

How to extract bootloader (boot.img) and

recovery (r

ecovery.img )_from any phone or KDZ?

A) There is very good procedure explained here by AngryWolf80. Please read and click THANKS button for him.

EDIT: Worked perfect on PC with ADB SHELL. (Hint: Give "su" command first)

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Q)

How to Run As Administrator? Where we find this command?

A) Please Google it. (trust me someone asked me this recently, well good news, not on xda :D)

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Q) How to start Service Menu (Hidden Menu) on L9?

A) To use Service Menu or Hidden Menu type 3845#*760# and call you will get Service Menu. This example is for 760, but you can enter 765 for P765 and so on. Dont actually mess with options as these are serious commands used by qualified service center engineers. Some options are easy to understand but most are not. So be careful and don't say I did not warn you if you lose network permanently. :D

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Q)

How to use DLNA of L9? (How to use L9 as Media Storage Device)?

A) I created one more Tutorial for DLNA connection of L9, here.

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Q1) I flashed JB 4.1.2/4.2.x, and found "/mnt/sdcard/0" folder. What it is? Can I remove it?

A) DO NOT REMOVE THAT FOLDER. Once I deleted it few weeks back and all of the folders on my External SDCARD got deleted. Later I discovered its mapped directory to various data folders on external card, etc. Looked at some places and found this useful information.

Source: http://rootzwiki.com/topic/37161-sdcard-0-folder/

In short in 4.1 and earlier the sdcard is physically at /data/media. In 4.2 its located at /data/media/0 or 1 or 2 and so on depending on the user. Their is one sdcard location mounted with fuse on all android versions for this phone and the rest of the locations are symlinks meaning you only have one copy of the data.

/storage/emulated/0 is the actual location in 4.2 that android and the PC look at and /storage/sdcard0 was for 4.1. Any other location than these and /data/media/0 or /data/media are symlinks.

And the interesting thing is that it wouldn't confuse anyone who is less knowledgeable but only those with some techie knowledge without a full grasp of the change. This is not against you but just an observation. I was a bit confused at first.

You shouldnt even be playing around with stuff in /data/media as it's not emulating a fat32 filesystem there and changing filenames results in them acting as they do on ext4 (which is case sensitive).

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Q) I am not able to get OTA/FOTA (Firmware Over The Air) update. What should I do?

A) This is not guaranteed will work for all, but worth trying. Well there is nice workaround if your phone is stuck and not getting OTA. Visit this post.