[Optimus One, P500, V General] doktornotor:
This HOWTO is for users who want to switch from stock LG 2.3.3 ROM to CM7 or other older ROMs that are NOT based LG's on v20? ROM or vice versa. Eventually, all new ROMs will switch to new baseband by default, so it is useful as well if you want to avoid the complete KDZ/Russian way flash which wipes everything.

Step 1:

- Download (see attachment) P500-v10E-baseband.7z or P500-v20G-baseband.7z

- unzip it via 7-Zip

Step 2:

- Browse to the folder where you unpacked the 7z and run LGMDP-v1.5.exe

- Click Download in menu

- Select Port

- Choose your phone, click Connect

- Click Image Folder button, browse to the directory where you unpacked this

- Click OK about 3 times on the warnings

- Do NOT mess with anything else. Leave everything else as is.

- Close the window

- Click Download button

- Let it do the job. It will backup your IMEI and MACs to .NV2 file, reboot your phone to emergency mode, flash recovery, reboot and restore the NV2 backup.

Step 3:

Congratulations. You are done! Now you can enjoy working GSM if you have installed the right baseband for your ROM. :p

Q: I am confused. Which baseband do I need?!?! I do not understand any of this!!!

A: Kindly re-read "Step 1: Do NOT proceed until you fully understand the following... " section. If you still do not understand after re-reading it a couple of times, then simply continue using your phone, do NOT flash anything and generally go on with your life. This guide is NOT for you. Kindly do NOT ask which baseband you should use here on the thread. The instructions will be updated if/when some ROM switches to the new v20g baseband by default.

Q: This appears dangerous. Is there an alternative for switching between ROMs based on LG's GB and others like CM7?

A: Life is dangerous. If you want to flash CM7-based ROM (like mik_os' CyanogenMod 7, andy572's Gingerbread ROM or Noejn's void. #forever)

and have the new baseband already

, there is a baseband fix by mik_os. However, due to a bug, data (2G/3G) unfortunately does not work at the moment. Wait for a new fix. If you have already flashed the mik's patch and want to undo it, flash REVERT-new-baseband-patch-signed.zip - you do not need to reflash the whole ROM. (Note: Only tested with mik's ROM! Do not complain if it does not work elsewhere.)

Q: But - I am a genius and came up with a better way to flash baseband! This one sucks!

A: If you come up with a way to flash the baseband via ZIP from recovery, kindly share it. :p

Q: My phone is not detected by the LGMDP-v1.5.exe utility! What to do?

A: Run devmgmt.msc (Device Manager), go to Ports (COM and LPT) and disable LGE Virtual Modem there. Disconnect and reconnect your phone and try again.

Q: I run the utility and the initial NV2 backup fails. What to do?

A: Disable the LGE virtual modem (see above), disconnect and reconnect the phone and try again. If it still fails, reboot your computer first before trying again. If it still fails, try to boot the phone to recovery (Home + VolDown + Power) or even emergency (Back + VolUp + Power) mode.

Q: Still have issues with phone not being detected or initial NV2 backup failing! Argh!

A: First of all, do NOT connect your phone to an USB hub with other devices connected! There will not be sufficient power for reliable phone connection. Otherwise, I would suggest trying this on another computer, or waiting for a better day. At minimum, clean all LGE drivers (set DEVMGR_SHOW_NONPRESENT_DEVICES to 1 in your Windows environment (kindly Google it), in device manager enable "Show hidden devices", uninstall all Android/LGE-related drivers, reboot your computer, reinstall the drivers.) Then try again. Anything else - you are on your own with high chances of bricking your phone.

Q: How do I know it worked?

A: If everything worked, you will have a working GSM (calls, 2G/3G data)

with the proper ROM installed.

. On stock ROMs, you can check the baseband version via hidden LG menu. It will show AMSS6150 if you flashed v20G baseband. If you see AMSS6038, then you have a baseband from v20[ABCD...] versions. If you see anything else, you have a baseband from v10? ROM. LGMDP utility also shows which ROM version does the baseband come from (see screenshot attached). Note (CM7 users): V07u-000-000-MAR-23-2009 is NOT your baseband version but some irrelevant CM7 crap.

Q: I would like to flash a custom recovery at the same time (I am on stock unrooted ROM, or just want to switch to another one, or whatever). Do I need to flash twice?

A: No, absolutely not. You can just download the recovery of your choice, stick recovery.img to the same directory where you have unpacked the baseband and it will get picked up and flashed automagically by the LGMDP utility! Chances to brick your phone reduced by 50% this way! :cool:

Q: I am not a moron! Did everything right but still have no GSM! What gives?!

A: You need to flash the right ROM for your baseband. Have you done that already (see the "Do NOT proceed" section)? :p

Q: I screwed big time, did not read the instructions and I now have no IMEI!!!! No GSM!!!!! My phone is useless!!!! You suck!!!!

A: You did not delete the backup, did you? If not, you can try restoring it via the utility. Otherwise - congratulations, you are a proud owner of a shiny hi-tech brick now. Go to LG service center and tell them that

Error ID-10-T

occured when using the phone.