Develop Bugs

[Q] Device won't connect to any network

Hi, I have an SGH-I747M that was originally purchased through Bell. In an attempt to unlock to make it work on Koodo, I went through SamMobile (after reading there was no way to unlock post 4.3 OTA update) and that seemed to half work.They resell a service from 123unlock.nl which is a client that uses adb or something of the sort to mess with phone files. The program afterwards said "Your phone is now unlocked! However if you don't see any carriers you need to do something in the advanced option and pay another $2x.xx dollars to do so". I didn't feel like giving them any more money at this point because I was upset that what I originally paid for didn't work properly. The fix was apparently an option in the advanced options that was an NVM repair/rebuild or something of the sort. I should have screenshotted the issue but of course didn't.
Now, the phone will boot up and does not offer me a SIM unlock option anymore. When searching for carriers it will ever only find Rogers for some reason. It won't recognize Koodo or Telus or anything of the sort (or bell when my bell SIM is in). Every now and then when it boots up, it will successfully send a text but only within a 5-10 second time frame after boot (I've made 1 phone call as well for 3 seconds). I've tried the Koodo SIM in my own Nexus 5 and works fine so the network is okay at least (plus I called Koodo and they verified on their end things look good... if that makes a difference). The SGS3 won't even accept an original Bell SIM at this point. It's always on either no network, 1 bar or full bars, never anything in between. I've tried flashing different ROMs from Bell stock to Koodo stock and CM11 and it won't work no matter what I do. Under all ROMs it pops up an "ME Returned temporary error" message on the screen.
I'm hoping someone might have seen this issue before or know what's going on with the phone that I can fix. I'm assuming it's something to do with the modem part of the phone that's refusing to connect to carriers but I'm at a loss to fix it. I haven't tried flashing different modems on it yet because I'm unsure which one would be a good fix and no one has had roughly the same issue I could find in 3 days of Googling for this issue. Any ideas are greatly appreciated. Thanks.

sgtcanadian said:
Hi, I have an SGH-I747M that was originally purchased through Bell. In an attempt to unlock to make it work on Koodo, I went through SamMobile (after reading there was no way to unlock post 4.3 OTA update) and that seemed to half work.They resell a service from 123unlock.nl which is a client that uses adb or something of the sort to mess with phone files. The program afterwards said "Your phone is now unlocked! However if you don't see any carriers you need to do something in the advanced option and pay another $2x.xx dollars to do so". I didn't feel like giving them any more money at this point because I was upset that what I originally paid for didn't work properly. The fix was apparently an option in the advanced options that was an NVM repair/rebuild or something of the sort. I should have screenshotted the issue but of course didn't.
Now, the phone will boot up and does not offer me a SIM unlock option anymore. When searching for carriers it will ever only find Rogers for some reason. It won't recognize Koodo or Telus or anything of the sort (or bell when my bell SIM is in). Every now and then when it boots up, it will successfully send a text but only within a 5-10 second time frame after boot (I've made 1 phone call as well for 3 seconds). I've tried the Koodo SIM in my own Nexus 5 and works fine so the network is okay at least (plus I called Koodo and they verified on their end things look good... if that makes a difference). The SGS3 won't even accept an original Bell SIM at this point. It's always on either no network, 1 bar or full bars, never anything in between. I've tried flashing different ROMs from Bell stock to Koodo stock and CM11 and it won't work no matter what I do. Under all ROMs it pops up an "ME Returned temporary error" message on the screen.
I'm hoping someone might have seen this issue before or know what's going on with the phone that I can fix. I'm assuming it's something to do with the modem part of the phone that's refusing to connect to carriers but I'm at a loss to fix it. I haven't tried flashing different modems on it yet because I'm unsure which one would be a good fix and no one has had roughly the same issue I could find in 3 days of Googling for this issue. Any ideas are greatly appreciated. Thanks.
Click to expand...
Click to collapse
Can you check your phone's settings => About Device and let's know what parameters you have there (Android Version, Baseband Version, Build Number>.
You mentioned you can send text or make call within a limited time frame. Was that with the Koodo SIM or the Bell? If the former, it would suggest the phone is unlocked to some extent but you are probably experiencing a baseband failure or need to correct the APN settings. Did you also try doing a factory reset?

Larry2999 said:
Can you check your phone's settings => About Device and let's know what parameters you have there (Android Version, Baseband Version, Build Number>.
You mentioned you can send text or make call within a limited time frame. Was that with the Koodo SIM or the Bell? If the former, it would suggest the phone is unlocked to some extent but you are probably experiencing a baseband failure or need to correct the APN settings. Did you also try doing a factory reset?
Click to expand...
Click to collapse
The information you're asking for is attached.
The texts I got off were from the Koodo SIM. I have updated the APN as well, and I did do a flash back to stock resetting all settings through Kies emergency update. I found a little trick where if you softbrick it by trying to flash 4.1, it'll give you the "Please use kies" error and that'll take you back to full stock 4.3. I'm pretty sure the baseband failure is the option I need to explore but at this point I don't know where to go to fix this.
Edit: I read this online and tried it: "The 4.3 update introduces a "security feature" which requires carrier- or region-locked phones to be activated once on the original locked network before the unlock code will work." The phone didn't recognize any network with the Bell SIM in except "EXT" which I've never heard of before and it did not connect properly so that didn't work. I also read that inputting #7465625*638*# will give me the Samsung SIM unlock menu which it did however I don't think the issue here is with the root and I'd hate to pay $50 at this point to have that not work as well.

sgtcanadian said:
The information you're asking for is attached.
The texts I got off were from the Koodo SIM. I have updated the APN as well, and I did do a flash back to stock resetting all settings through Kies emergency update. I found a little trick where if you softbrick it by trying to flash 4.1, it'll give you the "Please use kies" error and that'll take you back to full stock 4.3. I'm pretty sure the baseband failure is the option I need to explore but at this point I don't know where to go to fix this.
Edit: I read this online and tried it: "The 4.3 update introduces a "security feature" which requires carrier- or region-locked phones to be activated once on the original locked network before the unlock code will work." The phone didn't recognize any network with the Bell SIM in except "EXT" which I've never heard of before and it did not connect properly so that didn't work. I also read that inputting #7465625*638*# will give me the Samsung SIM unlock menu which it did however I don't think the issue here is with the root and I'd hate to pay $50 at this point to have that not work as well.
Click to expand...
Click to collapse
It's unlikely to be the regional lock as this feature means your phone will work with compatible networks in the region but not in other regions. You may, however, run Chainfire's Region Lock Away to be sure <http://forum.xda-developers.com/showthread.php?t=2470551>
Your firmware settings look OK so I'd be doubtful about a corrupted modem. You may still try to re-flash the modem via custom recovery. Download link for the CWM flashable zip is available here ... http://www.androidfilehost.com/?fid=23252070760973552
The guys who sold you the original code seem to have sold a dud as there is no reason for them to be asking for secondary payments and this sounds like the footprint of a regular scam. I'd be surprised though as they seem to be well rated

Larry2999 said:
It's unlikely to be the regional lock as this feature means your phone will work with compatible networks in the region but not in other regions. You may, however, run Chainfire's Region Lock Away to be sure <http://forum.xda-developers.com/showthread.php?t=2470551>
Your firmware settings look OK so I'd be doubtful about a corrupted modem. You may still try to re-flash the modem via custom recovery. Download link for the CWM flashable zip is available here ... http://www.androidfilehost.com/?fid=23252070760973552
The guys who sold you the original code seem to have sold a dud as there is no reason for them to be asking for secondary payments and this sounds like the footprint of a regular scam. I'd be surprised though as they seem to be well rated
Click to expand...
Click to collapse
I've tried reflashing the modem and I've actually paid $50 for the unlock code from Bell, the original carrier. I used the code to get the network unlock menu and inserted the code. I still get between 1-4 bars now with no network access on either network. It's not showing anything except Rogers still in network operator selection.
Any ideas at this point? It refuses to connect to any networks. I'm out of options.
Edit: I don't know if this makes a difference, but when I do root explorer I can't actually find the nv_data.bin file. It doesn't have anything of the sort in the /efs folder.

sgtcanadian said:
I've tried reflashing the modem and I've actually paid $50 for the unlock code from Bell, the original carrier. I used the code to get the network unlock menu and inserted the code. I still get between 1-4 bars now with no network access on either network. It's not showing anything except Rogers still in network operator selection.
Any ideas at this point? It refuses to connect to any networks. I'm out of options.
Edit: I don't know if this makes a difference, but when I do root explorer I can't actually find the nv_data.bin file. It doesn't have anything of the sort in the /efs folder.
Click to expand...
Click to collapse
Please let me understand a few things ... when you first acquired the phone, was it working normally on Bell prior to the first unlock attempt or you never used it at all until you tried Koodo? Secondly, was the unlock code you got from Bell identical to the one you got from the online service?
I'm trying to establish if it is a case of hardware failure not reported by the previous user especially if you bought it pre-owned from the secondary market. If you are not sure of the previous usage history, it could be a faulty or disconnected antenna which may require professional service. On the other hand if you are sure it was working fine prior to the unlock attempt, try the following ...
1) From the dial pad, enter *#197328640#
2) [1] UMTS
3) [1] DEBUG SCREEN
4) [8] PHONE CONTROL
5) [6] NETWORK LOCK
6) [3] PERSO SHA256 OFF
7) Press Menu => Back button and go all the way back to Step 3) above
8) [6] COMMON
9) [6] NV REBUILD
10) [1] NV REBUILD
Reboot and restart and let's see if this does it.

I've got a similar symtom different scenario (sister in-laws phone). I was also only able to see Rogers network on a search. I've got Telus version. It was working fine until it was brought to the Philippines, got unlocked there and brought back to Canada.
I was only able to see Rogers network until I went into the Service Menu (similar to above) and found the option to change the band. I changed it to Automatic. After that I was able to see Telus network. When trying to connect/register it would take a long time and give me an error "Unable to connect, try again later". I still need to do more troubleshooting, but that might be something to look at.
Note: Phone has stock MOD ROM, rooted and unlocked.

Locked bootloader, no baseband, greyed out OEM unlocking after flashing OCX27.109-36

Hello,
I have a problem with my Z2 Force TMO US version. I live in Poland. I bought the phone on the internet and it was TMO simlocked. I did the temporary unlock to check if it is working. Then I wanted to flash custom rom (DU in this case) and my problems has begun.
1. After first attempt of unlocking boot I got it unlocked but couldn't flash any custom rom. I figured out it is TWRP problem (flashed 3.2.2-2 not 3.2.1.1).
2. Flashed TWRP 3.2.1-1 and I was able to flash custom rom.
3. After flashing custom rom I lost phone signal: I'm getting no service and zero signal bar. I checked *#*#4636#*#* and noticed that I have radio off. I had IMEI and BASEBAND then.
4. I tried many other roms to get my signal back but no success.
5. I flashed stock TMO and was able to unlock simlock temporary again but it has no service and signal again. Radio is off.
6. Today I tried flashing stock OREO OCX27.109-36 with locking bootloader now I'm stuck.
I have locked bootloader and no baseband which means I don't have any signal or WIFI (mac is 0). I can't connect to google account so I can't get oem unlocking option - it's greyed out.
Can somebody help me with enabling OEM unlock? Or even better can somebody help me with getting signal back?
Thanks in advance for reply.

Try flashing the newest TMO firmware, which is the only thing you can flash with a locked bootloader. Check post #2 of the return to stock thread for the flashall utilities and the TMO flashall. The latest firmware provided for TMO is ocx27.109-51-7

You can do it
, I already had this issue with my moto z2 force in Morocco , so what I did is I connected the phone to internet via bluetooth and when I added my google accounte the unlocking oem in dev option was normal , so I was able to flash roms again . Hope this will help you.

Use pdanet app, you need two Android devices. Connect using Bluetooth...

Thank you guys. BT tethering helped. Thread can be closed.

How did you connect to Bluetooth to get through first start up? I can't get to Bluetooth settings to pair. I have this issue currently...

[GUIDE] Moto G7 Power/Supra [All Versions] Enable ALL LTE Bands (maybe?)

Note: I need some feedback to determine if this is *actually* working for people, since where I live, bands 2/4 are the main LTE bands for AT&T and T-Mobile and the International G7 Power (XT1955-2) supports those.
DISCLAIMER: I am not liable for any damage or legal liability caused by this guide or the improper application of it. As usual, do this at your own risk!
With that out of the way, lets do this:
You will need:
1. Your Moto G7 Power/Supra (any version). Not sure if you need to be rooted/bootloader unlocked or not. Mine is has already had both done. My guide to unlocking/rooting the G7 Power is here: https://forum.xda-developers.com/g7-power/how-to/versions-moto-g7-power-supra-magisk-t3923857
2. A usb cable to connect your g7 to a (windows) computer.
3. A windows computer.
4. Qualcomm QPST: (I used version 2.7.477) https://mirrors.lolinet.com/software/windows/Qualcomm/QPST/QPST.2.7.477.zip
5. Motorola USB Drivers: https://support.motorola.com/us/en/drivers
Step 1: Get QPST up and running
First download and install your Motorola USB drivers from earlier. Then download and install QPST. Boot your phone to the bootloader by rebooting and holding the volume down button or by turning off then holding power + volume down until the bootloader menu appears.
Using the volume up/down keys select "BP Tools" and then use the power key to boot the phone. Wait till its done then ensure USB debugging is turned off. If you dont know what that is, then it's probably off.
Go into device manager in windows by pressing windows key+r and typing devmgmt.msc. You'll see 3 devices under "other devices" without drivers (unless you got lucky and they automatically installed, mine didnt). We are intrested in the 3 that are named "moto g(7) power". We only need one of these, but its unclear what the correct one is, so repeat this process for all 3:
Right click and select "update driver"
Click "browse my computer for software"
Click "let me select from a list of availible drivers"
Scroll down to find "ports (com and lpt)"
Select "Motorola" as the manufacturer and "Motorola QC Diag Port" as the model
Ignore the "update driver warning" that comes up
Once you've got those installed, open QPST Configuration from the Start menu. It will show 3 devices, select the one that actually shows an esn. Then click "start clients" and then "Service programming"
Step 2: Unlocking the bands with QPST Service Programming
When QPST Service Programming opens, select your phone and hit OK. Then, click "read from phone" and wait a second for it to finish. Under the tab "UMTS System" you should see a bunch of checkboxes (most of them unchecked). At this point, you probably should click "Save to file" to backup what you're about to change.
You can select with the checkboxes specific bands you want to enable, but dont uncheck any that are already there. Alternatively you can do what I did and #yolo. Check "Any BC" to select them all. Dont mess with any of the other options but the "preferred bands" checkboxes because honestly I have no idea what that might do. When you're ready, click "Write to phone" and wait. I ended up getting an error that the "device stopped responding to read/write commands" and almost had a heart attack, but after closing and reopening QPST and clicking "read from phone" again, everything I had selected and wrote previously was still there.
Now, reboot your phone and give it a shot. You can confirm the changes stuck by booting back into BP tools mode through fastboot then opening QPST Configuration and the QPST Service Programming and clicking "read from phone" again.
Please let me know if this worked for you; if bands you previously could not get started working or if now LTE is working for you when it previously wasnt. You can check this by using the LTE Discovery app on the Play Store https://play.google.com/store/apps/details?id=net.simplyadvanced.ltediscovery&hl=en_US. As I stated earlier, bands 2 and 4 are the main LTE bands in my (rural) area so I cannot confirm this for myself. What I can confirm however that going through this process wont brick your device (unless you really screw up).
Thanks to samwathegreat for his guide here on getting the QC Diag drivers working/the phone showing up as a COM port which is required for this to work: https://forum.xda-developers.com/showpost.php?p=54338876&postcount=3
And thanks to bpear96 who made an older guide for older phones with an older QPST which I was able to graft into this guide for the G7 Power with the newer version of QPST: https://forum.xda-developers.com/moto-g/general/unlock-hspa-bands-moto-g-1700mhz-xt1032-t2878441
I'm still trying to get 5Ghz wifi working on the International model (XT1955-2) but am unsure if that's even a possibility. Any insight on that is welcome too .

Thanks for the great work, very hopeful that you can get 5Ghz wifi working. I've got the G7 power ordered, should be able to try out your guide in a few days, I'll let you know how it works.

Current status?
So its been a while whats the verdict is it possible? Also thanks for posting this guide.

magiricod said:
So its been a while whats the verdict is it possible? Also thanks for posting this guide.
Click to expand...
Click to collapse
Havent gotten any feedback regarding this yet, unfortunately.

Didn't work for me. I tried going old school by using QXDM/NV Browser and editing 06828 record, I think that was the record. It looked like it accepted the entry but the phone hung at boot and upon a second reboot the phone still didn't have the bands.
I also tried changing the device's information using fastboot oem hw utags but that seems to be a dead end. It seems there is an even lower system check before the bootloader/fastboot level. I think we may have to use edl and write the the modem. I just don't know enough about this low level stuff. Still researching though. I'm a little worried about pushing on because I can't afford replace the phone right now and not all the information on how to unbrick the phone is available yet.
I'm sure someone will figure out how to do it.

I tried this out but I haven't had any luck. It asks for a "Service Programming Code" when I try to "read from phone". If I bypass it, it will read, but when I try to write I get an error that it's not allowed.
Any ideas on where I could find the code?

So this is interesting, netmonster reports that I'm currently connected to lte band 66, although LTE Discovery says I'm on band 4. ??

diversenerd said:
netmonster reports that I'm currently connected to lte band 66, although LTE Discovery says I'm on band 4.
Click to expand...
Click to collapse
Has LTE Discovery been updated to show band 66? Last I checked it had not.

For me (XT1955-2) the screen is showing all bands already checked. The only checkbox disabled is the "Any BC".
I dont see 700Mhz but I see one checkbox already checked BC12 (I dont know if this is band 12). Please let me know whats happening...
---------- Post added at 02:33 AM ---------- Previous post was at 02:31 AM ----------

XT-1955-2: Bootloader unlocked and phone rooted.
Since I've had the phone it has been able to get LTE data pretty dang well on Verizon when set to LTE/CDMA ONLY, but can't make calls or SMS. I tried this method of checking bands but when I read from phone it has all bands checked already, except 'Any BC'. Just really hoping I can get this sorted out somehow.

So I have the metro version. It's unlocked, if I switch to visible I won't have access to the proper bands because of the metro rom?

Can someone please share a QCN file for a dual SIM variant?
I need it to compare to my single SIM one, cause I want to enable SIM2 but it has no IMEI.
halp pls?
also, when entering Service Programming Code, leaving it as 000000 doesn't throw any errors and reads well. Haven't tried writing though...

I tired it on my sim-unlocked Metro 1955-5, and did not give me any new LTE band options after i used the app provided..
btw, was the programming code supposed to stay at 00000?

Tolonus said:
XT-1955-2: Bootloader unlocked and phone rooted.
Since I've had the phone it has been able to get LTE data pretty dang well on Verizon when set to LTE/CDMA ONLY, but can't make calls or SMS. I tried this method of checking bands but when I read from phone it has all bands checked already, except 'Any BC'. Just really hoping I can get this sorted out somehow.
Click to expand...
Click to collapse
You get this sorted? I want to switch over to Verizon (tomorrow) but need confirmation that this phone will actually work with Verizon...
Software version: PPOS29.114-134-7
Stock Boot-loader.

illtww said:
You get this sorted? I want to switch over to Verizon (tomorrow) but need confirmation that this phone will actually work with Verizon...
Software version: PPOS29.114-134-7
Stock Boot-loader.
Click to expand...
Click to collapse
Well sorry to say it just isn't going to work with Verizon. This being double confirmed.

Followed steps, only thing not checked was Any BC, checked it, did the write and reboot and its still checked.
Does that mean its working?
Whats Any BC?
im on (XT1955-2)

Tolonus said:
Well sorry to say it just isn't going to work with Verizon. This being double confirmed.
Click to expand...
Click to collapse
It will work on any carrier the Sim has to be unlocked then u can use it any ware

diversenerd said:
Please let me know if this worked for you; if bands you previously could not get started working or if now LTE is working for you when it previously wasnt. You can check this by using the LTE Discovery app on the Play Store As I stated earlier, bands 2 and 4 are the main LTE bands in my (rural) area so I cannot confirm this for myself. What I can confirm however that going through this process wont brick your device (unless you really screw up).
.
Click to expand...
Click to collapse
So I have the -2 dual sim version, when I read from the phone i only had maybe 5 boxes checked off So I checked all boxes and wrote file to phone. all went well. rebooted and checked again and yes all were now active.
BUT I still do not pick up band 12. in my remote area I have band 2 and 12. side by side with my wifes LG she switches between band 2 and 12. and my moto g7 stays on band 2 then drops and has no service.
I still have no wifi calling or wifi texting with the phone. ready to throw it in the trash. any help would be welcome.

Question T-Mobile Oneplus 9 Pro: unblocking for EU SIM?

Hello Enthusiasts!
Is there a way to make T-Mobile OnePlus 9Pro (LE2127) work with an EU SIM?
I'm in Ukraine, and I already have T-Mobile Oneplus 7T Pro (McLaren), which started working with my SIM without effort. So that was a surprise when my new Oneplus 9 Pro, which I bought on eBay, rejected connecting to my local cellular network.
Is this problem solvable at all?
The phone is SIM unlocked, now I've also unlocked its bootloader via the official OP website. Perhaps, if I flash a Global EU ROM (https://forum.xda-developers.com/t/...7-to-eu-via-msm-no-unlock-bin-needed.4272837/), will the phone start seeing my local cellular network? I'm confused by several feedbacks in this thread from guys who have easily bricked their phones by trying to flash this Global EU ROM, so maybe there is no reason to take this risk if it will not solve the problem.
Kind Regards,
Vlad

I don't know of any issues doing MSM to EU firmware.
I've done it dozens of times on my T-Mobile phone that I use on a T-Mobile plan.
I can (and have) go back and forth between EU and T-Mobile MSM all day without any issues.
But please stay the **** away from the India MSM.
I think that's labeled "IU" or "IA" or something with an "I" in the name.
It supposedly will cause unresolvable issues trying to go back to T-Mobile firmware.

Validator1982 said:
Hello Enthusiasts!
Is there a way to make T-Mobile OnePlus 9Pro (LE2127) work with an EU SIM?
I'm in Ukraine, and I already have T-Mobile Oneplus 7T Pro (McLaren), which started working with my SIM without effort. So that was a surprise when my new Oneplus 9 Pro, which I bought on eBay, rejected connecting to my local cellular network.
Is this problem solvable at all?
The phone is SIM unlocked, now I've also unlocked its bootloader via the official OP website. Perhaps, if I flash a Global EU ROM (https://forum.xda-developers.com/t/...7-to-eu-via-msm-no-unlock-bin-needed.4272837/), will the phone start seeing my local cellular network? I'm confused by several feedbacks in this thread from guys who have easily bricked their phones by trying to flash this Global EU ROM, so maybe there is no reason to take this risk if it will not solve the problem.
Kind Regards,
Vlad
Click to expand...
Click to collapse
If it's sim unlocked, it should not be rejecting connection to your cellular network. Unless the frequency bands used in your area are missing from the modem. That also seems unlikely because the 9P has one of the widest coverages for bands of any OP phone. Maybe try selecting 4g/3g/2g default instead of 5g/4g/3g/2g.
(Settings->Wifi & Network->Sim & Network->Preferred Network Type)
Are you certain it's sim unlocked?
I am also on a tmobile 9P and used the msm->eu with no problem. I've done it a few times without problem going either way. But I don't know if that would solve your issue. Don't forget to back up your modem, persist, and modemst1/2 partitions before flashing the EU rom just in case. It won't hurt anything to flash the EU rom - you will be able to recover if anything goes wrong. And you'll get rid of the ugly ass tmobile branding. But you won't have the SIM unlock built in anymore so be certain your phone is currently PERMANENTLY Sim unlocked or you'll need to flash back to MSM->Tmo to use the built in unlocking app. If you are sure it's already permanently unlocked, give it a go Vlad

Thank you @CZ Eddie , @Appreciative for your answers.
I've validated here that there is definitely not a hardware problem with wireless bands support.
So now I understand that moving to Global ROM will not resolve the issue with "No carrier network". Googling the issue provided two more options:
1) try to switch the radio bands region via the menu in *#*#4636#*#* (the guy here described totally the same issue as I have). That didn't work for me, saying that it cannot switch the region to Europe (as well as to any other option);
2) try to erase modemst1, modemst2, as per the solution described in this video and also in this xda thread, but I'm again at risk of bricking the phone. At least, that was stated in the mentioned previously thread: *** Backup your working modemst1/2 and persist. If you lose these for any reason, it's unique to your device and not recoverable if you didn't back up (via MSM or other people).
Commands:
Take out sim
Bash:
adb reboot bootloader
fastboot erase modemst1
fastboot erase modemst2
fastboot erase cache
fastboot reboot
Insert sim
Am I right to understand, that I can use MSM to backup modemst1/2, then I could safely recover them back from the backup if my try with the second option doesn't help?

Validator1982 said:
Am I right to understand, that I can use MSM to backup modemst1/2, then I could safely recover them back from the backup if my try with the second option doesn't help?
Click to expand...
Click to collapse
That's supposed to be the case. MSM->F8, select is how I backed mine up.
I have read that if modemst1/2 is erased, it's restored/repaired/rebuilt from efs (or fsg) if available.
I've also read that when trying to restore modemst1/2 that it'll say fail to flash critical partitions and the suggested fix is to fastboot reboot fastboot while in fastboot. I haven't personally tried to restore my modemst1/2

Thank you @Appreciative !
I've hardly managed to put my OP9P to EDL mode and connect to MSM - after plugging in the phone with pressed +-, it was always trying to boot into OS immediately or soon after MSM told me it was connected.
Anyways, during those seconds while my phone was successfully connected to MSM I pressed F8, chose modemst1/2 options, and clicked on the 'Ok', but it asked me to provide a password. Is there any default password for MSM to do the backup, or do I need to ask TMO or OnePlus for it?

Validator1982 said:
Thank you @Appreciative !
I've hardly managed to put my OP9P to EDL mode and connect to MSM - after plugging in the phone with pressed +-, it was always trying to boot into OS immediately or soon after MSM told me it was connected.
Anyways, during those seconds while my phone was successfully connected to MSM I pressed F8, chose modemst1/2 options, and clicked on the 'Ok', but it asked me to provide a password. Is there any default password for MSM to do the backup, or do I need to ask TMO or OnePlus for it?
Click to expand...
Click to collapse
The password is oneplus and the files will be saved to C:/

I've managed to do the necessary backups via MSM, and then tried the following:
1) switched with MSM from TMO Android 12 to TMO Android 11 OS (11.2.6.6);
2) switched with MSM from TMO 11.2.6.6 to EU 11.2.2.2 (from the thread regarding the switching from TMO to EU) - here I'm still able to see and trigger "OEM unlock" in "Developer Options", successfully executed "fastboot OEM unlock";
3) applied OTA upgrade from EU 11.2.2.2 to EU 11.2.10.10 - here I see greyed "OEM unlock" in "Developer Options", but still able to successfully execute "fastboot OEM unlock";
4) applied OTA upgrade from EU 11.2.10.10 to Android 12 - here I already see LE2123 in "About phone", instead of LE2127 as before; I still see greyed "OEM unlock" in "Developer Options";
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Everywhere there I still wasn't able to make my SIM card to be connected to the cellular network even though SIM card itself was successfully detected.
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5) rolled back it all by switching back to TMO 11.2.6.6 via MSM. I got my bootloader locked and I still see greyed "OEM unlock" in "Developer Options". I've unlocked the bootloader via fastboot and my key file, but still wondering how to get ungreyed "OEM unlock" in "Developer Options". The Network Unlock status is "Permanent unlock".
6) I've tried to fastboot erase modemst1, but it told me that critical partitions were locked, so I cannot do that. I've also not found how to unlock that.
And my SIM is still unrecognized. So I got stuck.
Do you have any ideas?

Validator1982 said:
I've managed to do the necessary backups via MSM, and then tried the following:
1) switched with MSM from TMO Android 12 to TMO Android 11 OS (11.2.6.6);
2) switched with MSM from TMO 11.2.6.6 to EU 11.2.2.2 (from the thread regarding the switching from TMO to EU) - here I'm still able to see and trigger "OEM unlock" in "Developer Options", successfully executed "fastboot OEM unlock";
3) applied OTA upgrade from EU 11.2.2.2 to EU 11.2.10.10 - here I see greyed "OEM unlock" in "Developer Options", but still able to successfully execute "fastboot OEM unlock";
4) applied OTA upgrade from EU 11.2.10.10 to Android 12 - here I already see LE2123 in "About phone", instead of LE2127 as before; I still see greyed "OEM unlock" in "Developer Options";
----
Everywhere there I still wasn't able to make my SIM card to be connected to the cellular network even though SIM card itself was successfully detected.
----
5) rolled back it all by switching back to TMO 11.2.6.6 via MSM. I got my bootloader locked and I still see greyed "OEM unlock" in "Developer Options". I've unlocked the bootloader via fastboot and my key file, but still wondering how to get ungreyed "OEM unlock" in "Developer Options". The Network Unlock status is "Permanent unlock".
6) I've tried to fastboot erase modemst1, but it told me that critical partitions were locked, so I cannot do that. I've also not found how to unlock that.
And my SIM is still unrecognized. So I got stuck.
Do you have any ideas?
Click to expand...
Click to collapse
I can help you with getting the oem unlock toggle, using @Ju5t3nC4s3's tool here: https://forum.xda-developers.com/t/...ader-unlock-enabler-engineer-decrypt.4380419/
Although that doesn't solve your problem at all. There is a chance the tmobile variant (or any version I suppose) does not support the network in question at all. It could be missing the bands in the modem or maybe blacklisted on the network? I've read ATT blocks some OP devices from the network. Is it possible the device has a blacklisted imei? What carrier is the sim?

LGG4 H812 v20x Cannot unlock with USU in SALT, download mode not supported?

So I finally got mAid to work on another computer I'm using and I got the LGG4 H812 to connect to SALT and I tried unlocking with USU but I get the message "This download mode is not supported, downgrade to MM or LP." Even though I believe MM means "Marshmellow" and I thought the 20x firmware version COULD be unlocked anyways? The phone is the canadian version and the carrier is BELL though and I couldn't find any firmware with that specific carrier. So I'm not sure what to downgrade to or if I REALLY need to.
Also on a side note, when I tried using SALT to backup the phone, its always stuck at 0%, even on basic. it should be connected because I was able to reboot the thing with SALT so I'm not sure why it wont back up.