So I figured I would change this to a [HOW TO] and maybe be of assistance to future generations.
What is PRL, you say?
(Preferred Roaming List)
The PRL is a list of information that resides in the memory of some kinds of digital phones. It lists the radio frequencies the phone can use in various geographic areas.
The part of the list for each area is ordered by the bands the phone should try to use first. Therefore it's a kind of priority list for which towers the phone should use.
The PRL helps determine which home-network towers to use, and also which towers belonging to other networks to use in roaming situations (areas where the home network has no coverage.) When roaming, the PRL may instruct the phone to use the network with the best roaming rate for the carrier, rather than the one with the strongest signal at the moment.
Since a PRL tells the phone "where" to search for a signal, as carrier networks change over time, an updated PRL may be required for a phone to "see" all of the coverage that it should, both with the home network and for roaming.
Note for CM users: CM users will have to update their PRL through a Sense ROM. At this time CM does not support EPST codes.
-Do a full Nandroid Backup,
-after you do your Nandroid Backup wipe the Cache, Dalvik Cache, and Data,
-then flash a stock-based ROM (i.e., Fresh, Myn's, etc.),
-update your PRL,
-and then do a Nand Restore back to CM.
Note: Most people should be able to update their PRL through Menu > Settings > Systems Updates. For some this may not work (like me!), the instructions below should allow you to update your PRL manually from a file on your SD Card.
Here's what you need to do to manually update your PRL:
1. Download your desired PRL (I have attached the 3 newest versions below), unzip it, and save it to your SD card. I found This List from another post, which also links to This Thread on PPC Geeks.
2. If you are on a 2.1 or lower ROM skip to Step 6.
3. If you are runing a 2.2 or higher ROM, download the old EPST.apk (attached below) and save it to your SD card.
4. Use a Root Explorer (I used ES File Explorer), mount the system as R/W, and rename the EPST.apk file found in /system/app to EPST.tmp.
5. Now copy the EPST.apk you just downloaded from your SD card to /system/app, then tap and install it. Once the installation is done unmount the system and close your explorer program.
6. Open your dialer and dial ##775#, a prompt will appear asking for a password, you must enter your MSL here (I got mine from Sprint when I was having a problem with my ported phone number showing up).
6. After a moment you will see a list of all the PRL files on your SD card, choose the PRL file you wish to use and tap "OK".
7. Press the Menu button and tap "Commit Changes".
8. The phone should reboot itself after 10 seconds (you can tap "OK" to reboot immediately).
To verify: Menu > Settings > About Phone > Software Information (default...in CM it's listed under Status).
Note: Once you have updated your PRL, you can do a Nand restore and the PRL you just updated will remain in place.
I cannot take credit for any of this, I am just putting it all in one place to make it easier on n00bs like me!
Much thanks to the posts by: kperry1911, kyouko, myndwire (for the link to the Android forums which allowed me to find more info) and ch_ee_ko (which led me to kyouko's post)
***I will leave my original post in case it helps in people's searches***
Hey guys, wondering if anyone can tell me wtf?
I was on CM-6.1.1 and had PRL 60668, I flashed Myn's to update PRL, and now my PRL is 40434.
Tried again, it acted like it was updating, but no change. Flashed to Fresh 3.4 and same story, acted like it was updating but no change afterwards.
Thanks in advance, I poked around this forum, and I also tried XDA and Google search...Just found a bunch of unrelated crap.
*Edit* I have the newest Radio, PRI, and NV.
I just tried using fresh 3.5.1, stil no change.
I've now also tried using a stock rooted 3.7 ROM, still no dice. Any insight would be welcome! Thanks!
Sent from my PC36100 using XDA App