Develop Bugs

4G not working

Rooted my phone, now data connection works randomly on 4G. Usually works for about 5 minutes then nothing. Apps won't load nor does the browser. Any ideas on how to fix this?
Sent from my SGH-T989 using xda premium

I may very well be in the same boat as you. I got the phone the other day, brought it home, rooted it and went to work. Two mornings back to back at school my connection was hit or miss (mostly miss). Now today it seems to never have a connection unless I reset APN and reboot the phone. Contacted T-Mobile about possible issues and there was nothing they could suggest besides what I already tried. So of course the first thing I thought was it had to do with Odin and rooting. Does anyone else have anything about this? If rooting is causing the problem I have no problem going back to stock and keeping it clean. The only other thing I can do is bring the phone back, get a replacement, and try again. I'm 50/50 right now.

havent experienced anything like that on jugs or beastmod... try re-flashing your ROM

bobby3306 said:
havent experienced anything like that on jugs or beastmod... try re-flashing your ROM
Click to expand...
Click to collapse
Exactly, thats what everyone should do before creating new threads

Already reflashed rom. Even tried a different one. Still network is spotty.
Sent from my SGH-T989 using xda premium

Yea, no problems on Beastmod, its been my rom since I got the phone. NO ISSUES!! Try this however, 1. go into recovery, wipe cache, wipe dalvic, fix permissions, reboot. 2. Flash another radio and see what your results are with that. The KJ3 worked nice which is the dual banding telus radio. I recently switched back to KL1 to compare results. However, good luck and let me know what happened. Out of curiosity, what rom have you flashed?

iLeopard said:
Exactly, thats what everyone should do before creating new threads
Click to expand...
Click to collapse
http://forum.xda-developers.com/showthread.php?t=1467416
Surely he did not start a thread for no reason. Definitely not the only person with this problem. Not complete imbeciles.
Angstig gepost van mijn T989.
Juggernaut ROM
Faux kernel
-----
Gamertag: hompsar
PSN: OGhomp

[Q] Fried my GPS, not working at all on any roms.

I was flashing between CyanogenMod 10 nightlies and DrewGaren's Jelly Bean roms, wiping data every single time and always doing a clean flash when I noticed on CyanogenMod 10/05 nightly that the GPS wasn't catching any satellites at all. It doesn't seem like it's even trying because the GPS dot doesn't even come up in the notification bar. I tried using GPS Test and it just says 0. Same thing with any other GPS application.
I tried flashing to other roms to see if it changed anything and still no luck. Finally, I flashed all the way back to AT&T stock in ODIN and still no luck!! I'm thinking of just taking it to the AT&T store and see if they can do anything about it, I don't know the warranty situation since I bought it off of Craigslist. Anybody have any ideas?

Please don't go to ATT. We can't really help you since you bought it from a. craigslist and b. all we could do is get you to call warranty department in which case they may charge you since it was not purchased at the att store.

Do you know if the GPS ever worked??
Please go to dialer and type *#0*#. In that menu go to sensor test and make sure everything is working properly.
Go to http://forum.xda-developers.com/showthread.php?t=1767929 for a full list of tests you can do to make sure the phone is actually hardware damaged.
Sent from my SPH-L710 using xda app-developers app

Got it working
Hey, thanks for the help guys. I actually got it working. Flashed stock rom with ODIN and did a factory reset and it just started working out of no where. This was after 0 GPS signal on many different roms for over 24 hours.
No idea what caused it to stop working in the first place maybe some kind of conflict with the Drew Garen Sprint based Jelly Bean rom or maybe something in Cyanogen Mod 10/05 nightly. Perhaps the phone got tired of me flashing so many roms and just needed to rest overnight lol.
If anybody else has an issue with their GPS not catching signal at all flash all the way back to stock and factory reset and hopefully it'll sort the issue out.

Wow, everything you described in your OP is happening to me. I believe this happened to me after flashing DrewGaren's ROM too (4 point something). I tried it out then went back to Wanamlite, my DD, and experienced all that you said. After Wanam I flashed 2 or 3 other ROMs and got the same response... no GPS.
Just in the process of Odin flashing a stock image to see what happens.
Edit: Back to stock, then factory reset. Tried accessing the GPS service menu but that didn't work. Final result is that GPS is not working at all and here is no indication in the status bar. Looks like I'll be off to the Samsung store for service...

I think the Drew Garen Milestone 4.5 has something to do with this. It's based on the Sprint leak and maybe that made our GPS wonky.
Just to let you know, the stock firmware I used was this one.
http://samsung-updates.com/get/648/Samsung_Firmware_SGH-I747_ATT_I747UCALG1_Android_4_0_4.html
Hopefully you can get it sorted out. Just wondering, how do you access the GPS service menu? Cause the code I know doesn't work on AT&T Galaxy S 3 at all so I want to see if the code you tried works on mine. Good luck getting your phone working.

Another reason why you shouldn't use DG roms? Lol
I'm running insomnia leaks with no gps issues. Glad to see the OP got his working again.
Sent from my SGH-I747 using xda app-developers app

I did the same here is the fix.
Odin rooted stock ROM
Boot up as normal
Then do a factory wipe under settings.
You should be good to go.
Sent from my SGH-I747 using xda premium

beamer786 said:
I think the Drew Garen Milestone 4.5 has something to do with this. It's based on the Sprint leak and maybe that made our GPS wonky.
Just to let you know, the stock firmware I used was this one.
http://samsung-updates.com/get/648/Samsung_Firmware_SGH-I747_ATT_I747UCALG1_Android_4_0_4.html
Hopefully you can get it sorted out. Just wondering, how do you access the GPS service menu? Cause the code I know doesn't work on AT&T Galaxy S 3 at all so I want to see if the code you tried works on mine. Good luck getting your phone working.
Click to expand...
Click to collapse
Thanks for the firmware link but I am in Canada with Telus.
As for the GPS Service Menu, I saw some dialer codes for accessing it but they don't seem to work for our model.
It's weird how GPS doesn't show up anywhere on the phone now. Not the status bar or in battery usage stats. I am beginning to wonder if this is a hardware issue more than anything.

I know, it's like the GPS totally disappears from the phone, I thought it has a hardware issue too! I was actually on the phone with Samsung customer support and ended up fixing it while I was on hold.
On my first try I got no results too but when I downloaded the one from samsung-updates, flash via ODIN, and then factory reset the phone from settings that's when I finally got my GPS to work. They have the Telus software up there too if you want to give it a whirl. http://samsung-updates.com/get/2566/Samsung_Firmware_SGH-I747M_TLS_I747MVLALH1_Android_4_0_4.html
But at this point your only recourse might be to get done through Samsung customer support. Let us know what happens.

beamer786 said:
They have the Telus software up there too if you want to give it a whirl. http://samsung-updates.com/get/2566/Samsung_Firmware_SGH-I747M_TLS_I747MVLALH1_Android_4_0_4.html
But at this point your only recourse might be to get done through Samsung customer support. Let us know what happens.
Click to expand...
Click to collapse
Thanks, that is the exact firmware I flashed. Just in the process of downloading the I747MVLALE8 version. I know it's older but worth a shot.
I'll update the thread as I go along but am most likely going to the Samsung store in a week or two so there will be a delay in my response.

The disappearing gpshappened to me also. I flashed dg's m 4.5 and thats when I lost gps completely. I did all of the above mentioned in other threads and couldn't get it too come back. At&t replaced it for me. I would advise staying away from sprint leaks I guess.
Sent from my SAMSUNG-SGH-I747 using xda premium

Update:
Got in touch with Samsung. They forwarded me to the warranty repair company located in my neck of the woods (Vancouver, BC).
Company is called Service Absolut, located in Richmond around Westminster Hwy and No. 6 Road. There is another in Montreal for easterners.
Regular warranty service is 3 business days for $0 OR 3 hour express service for $30. This place isn't too far from my office so maybe I'll give the 3-day service a try..... on second thought I think the $30 might be worth it for same day service. :cyclops:

I ran into the same or similar loss of GPS on DG Milestone 4.5 and 5. I was able to regain GPS on a CWM restore back to Milestone 4.
Really think this is a ROM bug that can be fixed in SW. I'm surprised to hear that some have had much tougher luck than I have.
Anybody heard anything from Drew Garen? (I don't have enough posts to comment in the main thread, or I'd be there)

jpyeck said:
I ran into the same or similar loss of GPS on DG Milestone 4.5 and 5. I was able to regain GPS on a CWM restore back to Milestone 4.
Really think this is a ROM bug that can be fixed in SW. I'm surprised to hear that some have had much tougher luck than I have.
Anybody heard anything from Drew Garen? (I don't have enough posts to comment in the main thread, or I'd be there)
Click to expand...
Click to collapse
Yep, this is exactly what happened to me.
I flashed DG's M4.5 and my GPS quit working. Very weird.
I tried 3 other ROMS and no luck. I ended up returning the phone.
Now I really want to flash DG's new ROM but it scares me...ha

Final update:
Took the phone to the service center. Tech looked at the phone and tested but couldn't find anything wrong. He replaced the mainboard and all is now fine. GPS is working well.
Next thing is to check out my new CPU now... I hope it doesn't suck.

Did you factory reset on a stock rom like everyone suggested? I was reading your posts and I didnt see that you did it. Could have saved you $.
That issue used to happen to me all the time in the Infuse 4g.
Sent from my SGH-I747 using xda app-developers app

Jammol said:
Did you factory reset on a stock rom like everyone suggested? I was reading your posts and I didnt see that you did it. Could have saved you $.
That issue used to happen to me all the time in the Infuse 4g.
Sent from my SGH-I747 using xda app-developers app
Click to expand...
Click to collapse
Thanks for the tip but I factory resetted the sh*t out of my phone, lol. Our phone (Canadian version) only has 2 official firmware releases for it and I Odin'd them both and performed factory reset on both, multiple times. Guess I missed that little tidbit earlier
I really hope this was just a one time occurrence.

So I ran into this same issue, although it was from flashing Smartguy's ROM and then going back to CM10. It does seem to be caused by using the Sprint leak. I was unable to recover my GPS with the above method of flashing to stock via Odin and doing the factory reset.
I decided to try going back to my Sprint leak via a Nandroid, this brought my GPS back. I then used my CM10 Nandroid again GPS was working perfectly, although I needed to use GPS test to get it working on CM10. Hope this helps others with this issue.
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

Can't believe you had to go through all of that but glad you got it sorted. The price we pay for tinkering with our phones so much.
Sent from my SAMSUNG-SGH-I747 using xda app-developers app

Data issues

I keep getting data issues no matter what rom i flash. Ill have data one minute and out of the blue it goes out. Anyone else getting this?
White Hot! GS3.

Ive had bad wifi and updating the modem/radio fixed it. Someone once suggested data dropping can be caused by bad sim card.
Sent from my SGH-I747M using xda premium

LuRock said:
I keep getting data issues no matter what rom i flash. Ill have data one minute and out of the blue it goes out. Anyone else getting this?
White Hot! GS3.
Click to expand...
Click to collapse
Lu
U on JB or IC?
Had to leave JB because of this. Tried all the new rom's same thing. Leaving out of country so don't have time to check modems.
Let us know what u find.
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2

oldbbman said:
Lu
U on JB or IC?
Had to leave JB because of this. Tried all the new rom's same thing. Leaving out of country so don't have time to check modems.
Let us know what u find.
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Click to expand...
Click to collapse
Yea I was on Jedi Invasion Rom for 3 days with no issues but now all of a sudden Im getting this issue after trying other JB roms and even when coming back to Jedi Rom. data seems to be ok now but now i cant turn wifi On on any of the JB roms. Scratching my head on this one..
Oh well guess Ill head back to Triune for now. Have a good trip Old.
White Hot! GS3.

OK Old I'm back I tried to figure out why my data was tripping and why my WiFi was going on vacation on me but couldn't figure nothing out. I kept flashing a couple of different JB ROMs and even flashed a cm 10 JB ROM and still had the same issue. Also flashed 3 different modems but no luck. Now I dont know if it was the app i installed from the market called clean master to clean out all the junk from my phone or if its this last ROM(cm10 liquid smooth) i flashed that brought everything back to normal? You tell me!
I wonder what the thanks button is for?

I just had to recently revert back to ICS because of the my data being dropped through the whole day at work. I believe there is something wrong with the JB code. That is what I gather from the script readers at AT&T. Since I've been back on ICS I've even been able to squeeze out three extra hours of battery LOL!
AJ

is your imei intact? dial *#06# and make sure it's not 0

meanhacker said:
is your imei intact? dial *#06# and make sure it's not 0
Click to expand...
Click to collapse
Yes it is. At&t said my phone is the problem but when I reverted back to ice via Odin magically no data or dropped call issues.

oh alright sir. that's good to hear. did you have a backup image on your computer or you downloaded it from my thread?

meanhacker said:
oh alright sir. that's good to hear. did you have a backup image on your computer or you downloaded it from my thread?
Click to expand...
Click to collapse
I had a backup image on my computer. I.read this....its interesting and.may be a fix..
From a different forum by user Poseign:
I had this issue (the grey bars and no 4g/3g) about a week ago myself. Rebooting wouldnt fix it, resoring a nandroid wouldnt fix it, and I was starting to get worried that my radio hardware might have gotten borked.The fix was to clear my cache and dalvick cache. After I did that, my radio signal came back with no problems whatsoever. Coincidence? Maybe. But I'd like to think it wasnt

asjdwf said:
I had a backup image on my computer. I.read this....its interesting and.may be a fix..
From a different forum by user Poseign:
I had this issue (the grey bars and no 4g/3g) about a week ago myself. Rebooting wouldnt fix it, resoring a nandroid wouldnt fix it, and I was starting to get worried that my radio hardware might have gotten borked.The fix was to clear my cache and dalvick cache. After I did that, my radio signal came back with no problems whatsoever. Coincidence? Maybe. But I'd like to think it wasnt
Click to expand...
Click to collapse
Wish I could say this worked for me, but I've tried that and it did not fix it, the only solution I found was going back to IC from JB.
YMMV
Catching a flght back stateside, hope to be able to delve into this further later. Wish I knew what the issue was, but reading posts here on XDA there seems to be lots of issues by folks with new JB.

Ok wifi is good but every now and then I loose data completely for like 30 seconds and then pops up again. And I'm in a LTE area
I wonder what the thanks button is for?

After OTA 4.1.2 Update, having wifi issues/problem

I was using MrRobinson's stock rooted rom. When OTA 4.1.2 came out, I unrooted, installed patch, ran CF-Autoroot then I'm back to rooted again. However I did notice, every now and then, my wifi stays connected but connection dies. Internet connection is simply dead. So I don't get any email notifications if ever I get new emails. To fix this I have to turn wifi off/on and internet is ok again. I thought maybe I did something wrong so I wipe cache/factory reset, odin back to full stock non-rooted, installed OTA then use Exynos Abuse/Exploit to root. I am still experiencing the same issue. Att Smart Wifi is disabled. Wifi is always on under sleep policy. I have scorched the net and I can't find any solutions Any help would be much appreciated.

Mine is on the oem update no root even, and my wifi sucks now. The signal and connection will be good but it can't up or download anything. Wifi speed and cellular data speeds are all sub 1mbps also. ATT wifi is disabled also.
The only thing that helps me is to just pair to another wifi source, and go back if needed. Annoying! I'd love to find some solution also, I don't mind rooting if need be for it also.
Sent from my SAMSUNG-SGH-I317 using xda app-developers app

Had the same issue. I swapped it out for a new one and it is working fine now with the update
Sent from my SAMSUNG-SGH-I317 using xda premium

thephoneguyusa said:
Had the same issue. I swapped it out for a new one and it is working fine now with the update
Sent from my SAMSUNG-SGH-I317 using xda premium
Click to expand...
Click to collapse
Already have the phone more than a month, don't think I can swap it out
EDIT: Btw, no issues on custom roms, only having issues when using stock rom

ukic said:
Already have the phone more than a month, don't think I can swap it out
EDIT: Btw, no issues on custom roms, only having issues when using stock rom
Click to expand...
Click to collapse
You can still do warranty to get a new one just call att and tell them your situation with it. This would be my best recommendation to you. Or just root and keep running roms. This is one phone that I havent had the urge to customize with a rom or anything yet
Sent from my SAMSUNG-SGH-I317 using xda premium

thephoneguyusa said:
You can still do warranty to get a new one just call att and tell them your situation with it. This would be my best recommendation to you. Or just root and keep running roms. This is one phone that I havent had the urge to customize with a rom or anything yet
Sent from my SAMSUNG-SGH-I317 using xda premium
Click to expand...
Click to collapse
Thanks for the recommendation but I also felt the same before. I thought the phone was fast enough that I didn't need to try custom roms. After trying Scott's ATT CleanRom SE, that idea was simply change. If you haven't, you should try running custom roms. Although, I would still want to know if there is a solution to this problem when running stock rom.

ukic said:
Thanks for the recommendation but I also felt the same before. I thought the phone was fast enough that I didn't need to try custom roms. After trying Scott's ATT CleanRom SE, that idea was simply change. If you haven't, you should try running custom roms. Although, I would still want to know if there is a solution to this problem when running stock rom.
Click to expand...
Click to collapse
I've had similar issues since OTA upgrade to 4.1.2... Wireless auto connects to my wireless when i walk in the house, shows connected, but cannot actually download/upload/browse/etc unless i manually turn off wireless and then turn it back on, it reconnects, and works fine. Seems an issue the phone is having transitioning from celluar network to wireless...

willzilla said:
I've had similar issues since OTA upgrade to 4.1.2... Wireless auto connects to my wireless when i walk in the house, shows connected, but cannot actually download/upload/browse/etc unless i manually turn off wireless and then turn it back on, it reconnects, and works fine. Seems an issue the phone is having transitioning from celluar network to wireless...
Click to expand...
Click to collapse
Thought the question remains, why when using custom rom, you don't get this kind of problem...

ukic said:
Thought the question remains, why when using custom rom, you don't get this kind of problem...
Click to expand...
Click to collapse
Perhaps it's a minor bug somewhere and the custom ROMs happen to pull that wireless code piece from something other than official 4.1.2 where the bug (if it is one) is located.

willzilla said:
Perhaps it's a minor bug somewhere and the custom ROMs happen to pull that wireless code piece from something other than official 4.1.2 where the bug (if it is one) is located.
Click to expand...
Click to collapse
Yeah but hopefully it will get fixed soon. As I was looking for solutions, some people think it's their wifi routers that are having issues.

ukic said:
Yeah but hopefully it will get fixed soon. As I was looking for solutions, some people think it's their wifi routers that are having issues.
Click to expand...
Click to collapse
Perhaps it's an issue depending on what broadcast freq is being used by the router.

willzilla said:
Perhaps it's an issue depending on what broadcast freq is being used by the router.
Click to expand...
Click to collapse
True, but 4.1.1 didn't have this issue. They must have changed something.

I don't know if it is related to the issue in this thread, but I had a problem with the phone since I got it of the WIFI constantly connecting, then disconnecting, then connecting again. I solved it by changing the security model of the router from WPA/WPA2 to WEP128.

serpent2005 said:
I don't know if it is related to the issue in this thread, but I had a problem with the phone since I got it of the WIFI constantly connecting, then disconnecting, then connecting again. I solved it by changing the security model of the router from WPA/WPA2 to WEP128.
Click to expand...
Click to collapse
Yeah saw that thread somewhere but this is a whole different issue. Wifi stays connected but no connection to the internet. You get connection timeout.

Yeah mine just quits. A note 1, a note 10.1, 2 ipads, 2 iphone 4's, and xperia ion and three separate computers have had zero issues on any of the wifi networks here. In fact, if I leave it be, it will not work on the phone, and it now seems to block all the rest from access! If I turn the wifi off on this, perfect immediately afterward. Strange.
Sent from my SAMSUNG-SGH-I317 using xda app-developers app

did you try just simply reset your router?

I had all the problems in this thread after 4.1.2 A factory reset fixed it.

I'm using the international ROM (custom but fairly stock) and started experiencing the same issue when I switched ROMs.
Toggling the wifi always fixes the problem, but it's not a permanent solution. The problem seems to happen when the device goes into sleep mode for me.

Corvida said:
I'm using the international ROM (custom but fairly stock) and started experiencing the same issue when I switched ROMs.
Toggling the wifi always fixes the problem, but it's not a permanent solution. The problem seems to happen when the device goes into sleep mode for me.
Click to expand...
Click to collapse
Yep, when the phone goes deep sleep...

bobmay said:
I had all the problems in this thread after 4.1.2 A factory reset fixed it.
Click to expand...
Click to collapse
+1

A very weird problem.. I need some help with!

Ok, So I have an Epic 4g flashed to Cricket, I have made everything work(mms,test,talk,ect.) I have it on Android 4.1.2. My problem is I only get 3G and its not very dependable. I live in Phoenix, A.Z. Anyone have any ideas on what to do?

Did you change anything with the phone recently? Did you recently move homes?
Sent from my SPH-D700 using Tapatalk 2

Ihave not moved at all....
Sent from my SPH-D700 using xda app-developers app

shaunfrazier said:
Ihave not moved at all....
Sent from my SPH-D700 using xda app-developers app
Click to expand...
Click to collapse
Ok, and what of the first question.

How do I fix the data problem.. I can't just use 3g it not stable in phx. Goes in and out a lot even sitting still and not moving the phone.
Sent from my SPH-D700 using xda app-developers app

shaunfrazier said:
How do I fix the data problem.. I can't just use 3g it not stable in phx. Goes in and out a lot even sitting still and not moving the phone.
Sent from my SPH-D700 using xda app-developers app
Click to expand...
Click to collapse
Look, I'm trying to assist you. If all you are going to do is plead for help over and over again without providing answers, then I cannot help you.
Have you done anything to the phone since you last had stable connections?

nikon120 said:
Look, I'm trying to assist you. If all you are going to do is plead for help over and over again without providing answers, then I cannot help you.
Have you done anything to the phone since you last had stable connections?
Click to expand...
Click to collapse
I think he's implying that that's how it's always been, or possibly that he has done all of this within the last few days. However long it's been, to me it doesn't sound like a recent issue that has cropped up.
Just my obversvation though. Unfortunately that's all the help I can offer heh

Burban502 said:
I think he's implying that that's how it's always been, or possibly that he has done all of this within the last few days. However long it's been, to me it doesn't sound like a recent issue that has cropped up.
Just my obversvation though. Unfortunately that's all the help I can offer heh
Click to expand...
Click to collapse
Well, you're reading into what he typed; which means that he wasn't clear. lol

nikon120 said:
Well, you're reading into what he typed; which means that he wasn't clear. lol
Click to expand...
Click to collapse
haha Definitely no argument there! :highfive:

So hears what happen, I bought this phone 2 months ago I rooted the phone than flashed acouring to a tutorial I found on this site. (http://forum.xda-developers.com/showthread.php?t=780742)
After that I instealed the Provision Rom
(http://forum.xda-developers.com/showthread.php?t=2129233)
After that I flashed the Cricket mms fix found here
(http://forum.xda-developers.com/showthread.php?t=1649508&highlight=cricket+mms)
So I did not notice the 3g to 2g/1g switch because most of the time I am around wifi.. I have changed it since then or added anything.. I hope this is a better disription...
thanks

shaunfrazier said:
So hears what happen, I bought this phone 2 months ago I rooted the phone than flashed acouring to a tutorial I found on this site. (http://forum.xda-developers.com/showthread.php?t=780742)
After that I instealed the Provision Rom
(http://forum.xda-developers.com/showthread.php?t=2129233)
After that I flashed the Cricket mms fix found here
(http://forum.xda-developers.com/showthread.php?t=1649508&highlight=cricket+mms)
So I did not notice the 3g to 2g/1g switch because most of the time I am around wifi.. I have changed it since then or added anything.. I hope this is a better disription...
thanks
Click to expand...
Click to collapse
I don't use a MVNO, so I am not sure which regular troubleshooting steps would clear away your carrier settings. (I'm thinking using EFS Clear in Odin is the only concern, but that is sometimes needed for modem issues.)
Based off that rom's thread, you must be using the NS4G modem. Since your issue is with connectivity:
Perform a CWM backup of your current setup.
Flash an Epic modem rom and FC09 modem. (You can flash the modem using CWM. There's a thread in the dev forum w/ links.)
Try testing connection again.
I'd normally tell a Sprint Epic user to boot into FC09 multiboot and update profile & PRL, but I don't even think the PRL update would work for you. I'd then say, start from scratch by using Odin to flash FC09 with repartition checked. If they still had issues with connectivity, then I'd recommend using EFS clear in Odin when reflashing either just the FC09 modem or the entire FC09 tar.
Because you are on another carrier, I'm weary of suggesting you use Odin so quickly. If you haven't already, dive into your phone settings and document your carrier specific info you changed to get it working. This way, if you end up doing something that resets your original changes, then you can reconfigure it.
So give the suggestion that is listed above a try.

Since I'm very much a noob myself, I'm only tossing this out to possibly trigger an idea for someone else: Would perhaps the issue lie in the Build.prop or one of those similar files? I've poked around so many of them I can't remember which hold what tidbits of info... I know the Build.prop holds most of the primary carrier info, but I seem to recall another one that stored a bunch of info for a bunch of the other carriers (though that might have been for roaming and may not be of any help here).
*shrug* Otherwise, I's gots nothin' lol