[Defy Q&A, Help & Troubleshooting] zangetsu_MG:
Hello,

I have a MB525 that I purchased retail in the United States so it was never locked to any carrier. Currently I'm a T-Mobile customer and have no interest in changing that. I have to say I love this phone, mainly because it seems indestructible. Even years later the battery life is still good, but the stock 2.2.2 Froyo has become something of a problem because many of the Apps I would like to use have started requiring newer versions of Android.

I can't stay in the past forever, but I'm not quite ready to give up on this device so I started looking around at my options, and would you believe I found lots of other people who have this device and have worked very hard to produce updated Android OSes for it, and who have reported reasonably good success updating the device. I figured, Its already out of warranty, so I can't void a warranty I don't have. I also figured I'm a reasonably intelligent individual and have enough experience with Unix like operating systems that even if I get in trouble, I'll be able to ask the right questions to get out of trouble. Guess what point I have gotten to?

I started following the guide wikiDOTcyanogenmodDOTorg/w/Install_CM_for_jordan The Framaroot Gimli exploit worked great. I installed bootmenu 6.1 and Clockwork Mod Recovery. Fantastic. At this point, I was able to enter CMR and backup my mostly still factory ROM. If I understand correctly this is a nandroid backup. I copied that backup off of my SD Card to my PC. From this point I felt reasonably confident I could try things and in a worst case scenario restore to this backup.

Now I happen to have a stock ROM that seems to be a bit rare online, Blur_Version.34.4.806.MB525.Latam.en.01, so I figured at this point I'd do a service and create a backup using CWM after having done a factory reset. So I booted into the stock recovery, did a factory reset, restarted, and the OS was in a like new state. Perfect. Rebooted into CWM, and made a second backup of the factory reset state. I copied this off the SD Card to the PC. Now I figured I was ready for real fun.

I figured, I might as well put the most recent Android version I could find that people were reporting success with. This appeared to be [MENTION=505032]quarkx[/MENTION] Kitkat build. The thread is almost a year old and has 500+ replies and so I guessed that most of the major kinks would have been worked out by now. I followed the directions on quarx2kDOTru and installed cm-11-20141015-NIGHTLY-mb52x.zip from Quarx2k.ru, and low and behold it worked. CM11 booted and everything looked great. WiFi worked. Gapps worked. Play store started installing my apps.

There was one small problem. The phone refused to connect to T-Mobile at all. So I did the reasonable thing. I searched and learned about base band switching, and consulted T-Mobile on what would be the correct APN settings. Occasionally it would connect to AT&T for emergency calling, but it never connected to T-Mobile no matter what I did. From my home I was normally getting excellent signal on the stock ROM, so I am reasonably certain that the actual signal in the area was not the problem, and that this had to be some kind of configuration or software issue. A wiser person probably would have gotten on the forum and asked for help, but wisdom be damned, I wanted to do it for myself.

So more research and at some point I thought, Well, I'll go back to the Stock ROM so the phone will be usable again, and I'll take another crack at CM11 again later. It was at this point that I realized that CMR had been replaced with Team Win Recovery Project. This recovery looked to be more feature rich and easier to use, so I accepted that. I backed up my CM11 install. then went to restore my original backup. Well you might have guessed by now that TWRP and CMR don't use exactly the same backup formats. I saw no obvious way to get back to my backup and couldn't find information that would allow reinstalling CMR. This was the first warning signal I foolishly ignored.

At this point I started looking around for slightly earlier builds of CM11 that might not have had the the problem connecting to T-Mobile. Here is where things get fuzzy about how things got into this state, since the work was spread over two days at this point. Somehow between all the flashing backing up and restoring, the device got to a state where the OS never actually finished could do here is yank the battery and reboot into TFRP.

At this point, attempting to restore would just result in the messages 'E: Unable to mount '/cache' and 'E: Unable to mount '/data' in the terminal. So After searching around I learned that I probably needed to format /cache and /data because somehow they were broken. Terminal commands, I can handle this. I start reading up and find the correct command and parameters for the format, and I type into the terminal inside TWRP and low any behold format can't be found. I start looking around the directories in my file system from inside TWRP and I've got a complete directoty structure, but no files in any directories other than on /sdcard. Well fuuuu.

Not sure what made me even try, but copying any file from my sdcard into /data somehow put /data into a state where a TWRP restore would work. So at this point I was able to restore the CM11 backup, and my phone now boots into CM11, 11-20141007-NIGHTLY-mb526. But.... the cellular network still doesn't work.

But now I am wiser and I am back to the point where a wiser person would have asked for help. So... Help?

Is 11-20141007-Nightly-mb526 the best rom an appropriate rom for my device? I'm guessing I missed something because other discussions on this forum mention newer builds, and also, my device is definitely a 525 not a 526.

Is my baseband version EPU93_U_00.60.03 right? The baseband selector allows me to pick from three T-Mobile settings: 3.4.2.-107-4, 3.4.2.-107-9, and 6.xx.0, none of which seems to allow me to connect to the cell network.

Thanks in advance for any assistance offered.

Sorry for the long potato.