BACK UP YOUR ROM NOW please, i am not responsible for any data loss or anything breaking on your phone if you follow this method
we will not be using baseband fixes and kernels here because sometimes they work sometimes they do not. They are not reliable.
In this example i will be using pac rom for the p500 which, if you flash it, you will notice that the colors are XXXX-ed up. that is a baseband issue.
Step 1) Back up your current rom
Step 2) Download - put on sd card - flash this rom : http://jenkins.androidarmv6.org/job/android/369/
-this is the lg thrive cm10.1.1 android 4.2.2 rom. in has a built in kernel (boot) which we will need.
Step 3) Back up this rom ^^ once you have flashed it. (dont do gapps and all the other stuff cause its not needed)
Step 4) Once backed up, download the rom you want (miui v4 or v5, cm 10, pac rom, aokp, ANYTHING that is for the lg p500 and is new baseband only)
Step 5) Obviously, get the gapps and all that good stuff.
Step 6) Flash the rom (pac rom, paranoid android, aokp, miui, etc) (DONT FORGET TO> wipe data, cache, dalvik, system, boot)
Step 7) Flash Gapps (if needed, i usualy just keep a back up of all the play store and download the apps i need, this saves system space on start up)
Step 8 ) (notice, you never existed the recovery) Go to back up and restore, and do ADVANCED RESTORE, select the cm10.1.1 rom that i mentioned in step 2, and pick BOOT
Step 9 ) Reboot. check if everything works fine. if it does not boot, then this method does not work for this rom, although it should work on any rom (tested on aokp, pac rom, miui v4)
Step 10 ) CHECK if you have service (if needed) if you dont, flash this : http://www.mediafire.com/download/rp...-Fix-OldBB.zip
Step 11 ) YOU ARE DONE
hope this helps, please leave feedback if this method works. this should work on any old baseband phone that is trying to run a new baseband rom.
If you want cm 10.1.1, go here and find your device on the left : http://jenkins.androidarmv6.org/job/android/
each of the p500+ roms has the same "boot"/"kernel" so it should be universal. so if you have old baseband p500, not p506, just flash the cm10.1.1 for your device.
Thanks to all the great devs out there who make these roms, and really never care about making it work on multiple devices (except rashed )