[Optimus One, P500, V General] bambu85:
Fixing mobile data (3g) after installing Cyanogenmod 7 (nightly)

Hello all. I'm writing this as a long-time lurker and custom ROM / kernel user, who has been helped along greatly by this forum.

I had a long-standing issue that I couldn't find any clarity on: my mobile data access didn't work after switching to custom Roms/Kernels from LG's original Froyo Rom.

After months of thinking it was just an odd bug, and something to live with (since I rarely use data), I decided to look a little deeper into the problem. I found it difficult to even find information on the problem - there's a lot of bad information, and a lot of hard-to-read information from friendly, but not perfectly fluent English speakers.

In short, I'm hoping that others who are struggling with this issue will find this post with some Googling, and won't have to be as confused as I was.

After doing the following, I have everything working perfectly and here's how I did it:

1) I knew that the right baseband (under About Phone, in Settings) had something to do with mobile connections, including 3g data authentication and transfer. I found that v10 (and older) basebands are considered the 'old' baseband, while v20 basebands are considered 'new' basebands.

2) Cyanogenmod often reports the baseband incorrectly, so finding out what baseband you're on is unreliable through the About Phone menu, if you're already on CM7.

3) There are some scary sounding techniques to update your baseband (one involves using a poorly documented program called 'LGMDP-v1.5.exe'). These techniques can apparently brick your phone, so I avoided them. I might be wrong on some of the details here, so let me know!

4) I instead obtained the latest baseband by simply letting the LG update software (in my case from LG.ca) update my phone to Android 2.3. I noticed that I now had baseband v20.

My mobile data worked

!

5) I then re-rooted the phone, using SuperOneClick.

6) Installed the latest CM7 nightly.

Mobile data no longer worked

:(

6.5) I should mention, I tried other ROM/Kernel combinations and ended up having crashes and hangs on boot - thankfully I could use 'adb reboot recovery' to get back to Clockwork Recovery, when even holding various keys on reboot to do this didn't work).

7) Installed the wonderful ta-gb 1.1 kernel (thanks to all of the devs who worked on this and others like it).

8) And lastly (and possibly most importantly) I came across this:

https://github.com/CyanogenMod/andr...gingerbread/prebuilt/common/etc/apns-conf.xml

It's a list of APN information, which corresponds to different carriers, and appears to be necessary for mobile data connections. My carrier (Koodo) was not listed here, and therefore appears to not be included in even the latest Cyanogenmod 7 (as of Feb 2012).

9) This led me to find this: http://code.google.com/p/cyanogenmod/wiki/APNlist

Which happened to include the APN information for my carrier that I needed to put in, under Mobile Networks > Access Point Names.

Inputting that information made my 3g connection start up instantly

. I was able to check that things looked good by typing *#*#4636#*#* in the dialer, and looking under Phone Information.

Maybe you're a veteran CM7 user, and think this is obvious newb stuff, but I want to leave this thread here for any other users who were stuck as long as I was.

If you fixed this issue with a different method, please share what you did here. If you're a ROM/Kernel dev with more insight on anything that I covered, please comment.

Cheers.