[T-Mobile LG G2x] Core Memory:
Original Post

I started up the LGMobile Support Tool and selected supported model. When I scrolled down, it shows new firmware, V21y, for the LGP999DW, LGP999DWDU, LGP999DWP but still shows V21e for the LGP999WA.

Update 4/20/2012

The V21Y_00 update (LG T-Mobile branded Android 2.3.4) is not available anymore through the LGMobile Support Tool and LG has removed the direct download link to the V21Y_00.kdz file. Instead, thanks to another member, overground, it is now available from http://www.mediafire.com/?obr7717n1ebj2qa

Get it while you can in case LG files a DMCA complaint against Mediafire.

overground

Today, 12:48 PM

# 315

Yeah, seems LG has removed the update from their servers.

I've uploaded V21y here = http://www.mediafire.com/?obr7717n1ebj2qa

@CoreMemory: Feel free to put the link in the OP.

IMPORTANT!

A lot of peeps have had trouble installing the V21Y_00.kdz file. There are many variables which can cause installation failure which are due to "operator error" and/or computer idiosyncracies. This thread and others have information about various methods used to overcome update problems so, if at first you don't succeed, read the thread(s) and keep trying.

As well, this update will install a new baseband and an LG and T-Mobile branded Android 2.3.4 ROM. LG has made some serious changes to the baseband which prevents other ROMs, except for a modded version of the same Android 2.3.4 ROM or the newest versions of CM7 and some other ROMs (which you can find by searching for compatibility with V21Y/March baseband), from working with in-call audio which is the audio for using the phone as a phone - to make and receive phone calls and for the people on each side of the connection to hear each other. So, if you want to install modded ROMs, other than the a modded version of the V21Y Android 2.3.4 ROM installed by this update or one such as CM7 which is compatible (Weapon isn't), don't update. If you do install it you can revert back to V21e by downloading it and using whatever method you used to successfully install the V21y update.

Before you update to V21Y, save a CWM backup of your existing ROM which you can use to revert back to the installation you now have after you reinstall V21E (including the V21E baseband). You can't use CWM to reinstall V21E, you must use the KDZ updater with the V21E kdz file then use CWM to restore your previously installed V21E modded ROM and Kernel. Good Luck!

If you want to revert to V21E Android 2.3.3 and the compatible baseband, get the V21E kdz update file here: http://www.2shared.com/file/WVH0y09f/V21E_00.html

INSTRUCTIONS

There's usually no need to revert your phone back to a stock ROM. If you use the following method, you can install any G2X/P999 .kdz update file (V10f, V21e, V21y, etc.) over

almost

any ROM, including modded ones. If you want to eliminate a potential update problem, revert to a stock ROM first. If the update didn't work, and you bricked your phone, you need to revert back to a stock ROM which you can do by following the instructions here: http://xdaforums.com/showthread.php?t=1248644&highlight=unbrick+phone

I successfully used Windows Virtual PC in XP Mode to install the .kdz file but you may be able to install it in Windows XP and Windows 7 (32 and 64 bit), as others have successfully done, by using LG_KDZ_FW-Update_OfflineFix as follows:

First,

From the OP by adixtra at http://xdaforums.com/showthread.php?t=1287236

1. download: LG_KDZ_FW-Update_OfflineFix (OFFLINE INSTALLER DOWNLOAD)

2. download: KDZ_FW_UPD_EN (DOWNLOAD FLASHING PROGRAMS)

3. download: ROOT USING SuperOneClick

DO NOT DOWNLOAD ANY OF THE OTHER FILES THERE!

Alternative to downloading the #1 and #2 files listed above,

here's a link to instructions and files, by spyrosk, which includes almost everything (except for SuperOneClick and the .kdz update file) which installs and runs by using an included VB Script: http://xdaforums.com/showpost.php?p=22189294&postcount=30

You will still need the .kdz file of your choice to use with it.

Second,

Download the V21Y_00.kdz upgrade/update file which, although LG has removed the V21Y_00.kdz file from their server, thanks to another member, overground, it is now available from http://www.mediafire.com/?obr7717n1ebj2qa

Third,

From the OP by Kairi_zeroblade at http://xdaforums.com/showthread.php?t=1566681

download CWM-Based Recovery 5.0.2.8

Fourth,

Carry out the steps in adixtra's OP at http://xdaforums.com/showthread.php?t=1287236 with the V21y_00.kdz file you downloaded by selecting it from wherever you downloaded it to.

It takes about 10 minutes to complete.

Fifth,

Afterwards, you will have to root it with SuperOneClick and install CWM if you want to use it for backing up, restoring, etc. (saving your butt) otherwise if you restore it will be the stock v21y installation.

XP MODE Instructions

If you don't succeed with Windows 7 or Windows XP (which it should have), it may work with XP Mode in Virtual PC. The LG Modem drivers have to be installed in Windows 7 first then, after you get XP Mode operating, carry out the steps again. After you connect the phone to the computer, you will have to attach the phone's USB port in XP Mode from the XP Mode USB menu. During the update process, the phone's USB port will detach, you'll hear an alert sound, and you must reattach the USB port again from the XP Mode USB menu. That will happen a few times until the process completes. Here's instructions from Microsoft about how to install and use Windows XP mode in Windows 7 http://windows.microsoft.com/en-US/windows7/install-and-use-windows-xp-mode-in-windows-7.

Also,

Have a look at Enyah's thread for information about how others have successfully updated to V21Y_00.kdz http://xdaforums.com/showthread.php?t=1610597

Have a look at Rafase282's post too, it repeats some content from my thread and others' but has some additional content http://xdaforums.com/showpost.php?p=26935107&postcount=3