LG G4 H812 (Canadian) Intermittently No Service

[threehappypenguins]

I found a used LG G4 that was locked to Koodo for a friend of mine. I researched to make sure that it supports the AWS 1700/2100 band since my friend is on Eastlink (similar to Freedom Mobile). At first everything worked fine, but now he is getting intermittent disconnections from the network where it says "no service." I had him choose the option without LTE, and at first he got service again, but then he didn't get mobile data, and the connection randomly dropped anyway (for calls and texts).

I had him open the service menu via *#*#4636#*#* to turn off the radio, but as soon as he goes to "Phone Information," he gets the message "This application does not work on this device." So Koodo blocked the menu. Wonderful.

At this point, I'm really not sure what to do. Has anyone had similar issues? I've rooted and installed custom ROMs on my own phones several times before. Would installing a custom ROM help? Or maybe just flashing another modem file?

If anyone could help, it would be greatly appreciated. I was trying to help my friend save some money. His old phone was 8 years old and was a cheapo that was laggy from the start. I recommended a "higher end" used phone rather than another cheapo. He's running a business and has 9 kids, so... I would really like to get this working for him.

Edit:
Problem is solved. My friend is no longer experiencing intermittent "no service'" or anything. Here is what I did:

1. Followed these instructions to unlock the bootloader.
2. Flash stock Nougat zip (instructions also say "After that and while still in TWRP: Choose Reboot -> RECOVERY ! This should ensure TWRP will not be overwritten on Android boot")
3. Flash Nougat modem zip
4. Flash my model's baseband (again; was already done during bootloader unlock)

I realize now that I might have not needed to unlock bootloader at all, and could have used LG Up (new) to flash a kdz. But oh well, it's all done, and now my friend has Nougat (the Canadian variant abandoned updates before Nougat).

 

[sdembiske]

I found a used LG G4 that was locked to Koodo for a friend of mine. I researched to make sure that it supports the AWS 1700/2100 band since my friend is on Eastlink (similar to Freedom Mobile). At first everything worked fine, but now he is getting intermittent disconnections from the network where it says "no service." I had him choose the option without LTE, and at first he got service again, but then he didn't get mobile data, and the connection randomly dropped anyway (for calls and texts).

I had him open the service menu via *#*#4636#*#* to turn off the radio, but as soon as he goes to "Phone Information," he gets the message "This application does not work on this device." So Koodo blocked the menu. Wonderful.

At this point, I'm really not sure what to do. Has anyone had similar issues? I've rooted and installed custom ROMs on my own phones several times before. Would installing a custom ROM help? Or maybe just flashing another modem file?

If anyone could help, it would be greatly appreciated. I was trying to help my friend save some money. His old phone was 8 years old and was a cheapo that was laggy from the start. I recommended a "higher end" used phone rather than another cheapo. He's running a business and has 9 kids, so... I would really like to get this working for him.

Assuming he's carrier unlocked, if he's using an old sim card from a previous carrier, he should purchase a new sim card from his current carrier.
If he hasn't already tried this, suggest he do a network reset: Settings > Backup & reset > Network settings reset.
If no go, his alternatives are to (assuming he's not bootloader unlocked): try a factory reset; next, re-flash his appropriate kdz in LGUP-NEW. He should backup his userdata first.
If bootloader unlocked (UsU) he could re-flash his modem.bin or modem.img file from a SALT extract of his appropriate kdz.

 

[threehappypenguins]

Assuming he's carrier unlocked, if he's using an old sim card from a previous carrier, he should purchase a new sim card from his current carrier.
If he hasn't already tried this, suggest he do a network reset: Settings > Backup & reset > Network settings reset.
If no go, his alternatives are to (assuming he's not bootloader unlocked): try a factory reset; next, re-flash his appropriate kdz in LGUP-NEW. He should backup his userdata first.
If bootloader unlocked (UsU) he could re-flash his modem.bin or modem.img file from a SALT extract of his appropriate kdz.

I've already done a factory reset of the phone. Is a network reset necessary, or would the factory reset cover that? His bootloader is not unlocked... yet. I will attempt re-flashing his kdz and/or just the modem if the network reset at this point is unnecessary. I'm looking at lg-firmwares.com and don't see Koodo on that list (the phone was originally put out by Koodo), so I assume Telus (Koodo's parent network) would be a safe one to use (MM)?

 

[threehappypenguins]

I found a bigger list here. I found the link in this guide.

 

[sdembiske]

I've already done a factory reset of the phone. Is a network reset necessary, or would the factory reset cover that? His bootloader is not unlocked... yet. I will attempt re-flashing his kdz and/or just the modem if the network reset at this point is unnecessary. I'm looking at lg-firmwares.com and don't see Koodo on that list (the phone was originally put out by Koodo), so I assume Telus (Koodo's parent network) would be a safe one to use (MM)?

Network reset is your first & best option. Re-flashing the kdz is your last option.

Use this site for the kdz download and scroll down to and use this Telus kdz ( H81220z_00_0327.kdz: it does work on Koodo as well): https://lg-firmwares.com/lg-h812-firmwares/firmwares/

Refer to this link for flashing with LGUP-NEW: https://forum.xda-developers.com/g4/help/lgup-install-kdz-mm-lp-t3249803

As a 'Senior Member" you should know that it is an XDA courtesy to use the Thanks button - you should have learned to use it by now - bottom right of the post

 

[threehappypenguins]

Assuming he's carrier unlocked, if he's using an old sim card from a previous carrier, he should purchase a new sim card from his current carrier.
If he hasn't already tried this, suggest he do a network reset: Settings > Backup & reset > Network settings reset.
If no go, his alternatives are to (assuming he's not bootloader unlocked): try a factory reset; next, re-flash his appropriate kdz in LGUP-NEW. He should backup his userdata first.
If bootloader unlocked (UsU) he could re-flash his modem.bin or modem.img file from a SALT extract of his appropriate kdz.

Network reset is your first & best option. Re-flashing the kdz is your last option.

Use this site for the kdz download and scroll down to and use this Telus kdz ( H81220z_00_0327.kdz: it does work on Koodo as well): https://lg-firmwares.com/lg-h812-firmwares/firmwares/

Refer to this link for flashing with LGUP-NEW: https://forum.xda-developers.com/g4/help/lgup-install-kdz-mm-lp-t3249803

As a 'Senior Member" you should know that it is an XDA courtesy to use the Thanks button - you should have learned to use it by now - bottom right of the post

Thanks! I am getting him to do a Network settings reset right now. I'll wait and see if that resolves the issue. If it doesn't I will attempt flashing.

I do have a question about the bootloader. You said that it is required to be unlocked. But I read that on the H812 you can't unlock the bootloader. So how does that work? Can I just flash a Marshmallow kdz onto the existing MM OS? I see that his current software version is H81220z. I thought that since there is no root (and no bootloader unlock?) for MM, that I have to downgrade to Lollipop (as explained in these instructions). I thought an unlocked bootloader is always a prerequisite?

 

[threehappypenguins]

Aha! I searched and searched and eventually found this key post. It points to this thread here about (kind of, sort of) unlocking the bootloader and also recommends a backup with SALT.

 

[sdembiske]

Aha! I searched and searched and eventually found this key post. It points to this thread here about (kind of, sort of) unlocking the bootloader and also recommends a backup with SALT.

Yes, quite a number of us now have unlocked our bootloader, thanks to the unwavering steadfastness of @steadfasterX, author of the UsU unlock method.
Ensure you do upgrade to the latest Telus 1220z MM kdz (even though he is on it already), I linked first with LGUP-NEW to see if the network connection is restored and then do a SALT backup as recommended before unlocking. It is very important you read the OP in the USU unlock thread thoroughly, making sure you understand it complete;y, to avoid easily avoidable screw-ups. You should make sure your friend understands the process and risks as well before proceeding.

steadfasterX has also prepared custom roms for our unlocked H812's and I can recommend both the ASOCP N and the Lineageos O roms for your H812, if your friend doesn't rely on any LG stock proprietary apps, otherwise you can flash him a special stock Nougat LG rom (all available in the Downloads section in the UsU thread).

 

[threehappypenguins]

Yes, quite a number of us now have unlocked our bootloader, thanks to the unwavering steadfastness of @steadfasterX, author of the UsU unlock method.
Ensure you do upgrade to the latest Telus 1220z MM kdz (even though he is on it already), I linked first with LGUP-NEW to see if the network connection is restored and then do a SALT backup as recommended before unlocking. It is very important you read the OP in the USU unlock thread thoroughly, making sure you understand it complete;y, to avoid easily avoidable screw-ups. You should make sure your friend understands the process and risks as well before proceeding.

steadfasterX has also prepared custom roms for our unlocked H812's and I can recommend both the ASOCP N and the Lineageos O roms for your H812, if your friend doesn't rely on any LG stock proprietary apps, otherwise you can flash him a special stock Nougat LG rom (all available in the Downloads section in the UsU thread).

My friend's phone says that it's MM and software version is H81220z, so he should be good there.

I'm interested in Lineage Oreo, and I'm a little confused about the instructions, if you don't mind enlightening me. So first off, I understand that UsU is required first. In the UsU instructions, it says:

Flash the baseband package now: <model>_UsU_baseband_flash-in-twrp.zip

But in the Lineage O instructions, it says:

If you have ever flashed the UsU baseband package: Clean flash the modem partition from your backup in TWRP.

So I assume that I'm supposed to just skip flashing the baseband in the UsU instructions? What about installing SuperSU afterwards? Is flashing that new baseband required?

I guess what I'm wondering is, should I flash the baseband, like in UsU instructions, then revert back to the original baseband, like in the Lineage O instructions, or should I just skip flashing the baseband in the first place?

 

[sdembiske]

My friend's phone says that it's MM and software version is H81220z, so he should be good there.

I'm interested in Lineage Oreo, and I'm a little confused about the instructions, if you don't mind enlightening me. So first off, I understand that UsU is required first. In the UsU instructions, it says:


But in the Lineage O instructions, it says:


So I assume that I'm supposed to just skip flashing the baseband in the UsU instructions? What about installing SuperSU afterwards? Is flashing that new baseband required?

I guess what I'm wondering is, should I flash the baseband, like in UsU instructions, then revert back to the original baseband, like in the Lineage O instructions, or should I just skip flashing the baseband in the first place?

The reason you should re-flash the same kdz, is to see if it gets the network connectivity issue solved before proceeding with anything else as you may find the problem still exists.

If you are planning to go the the LG Nougat stock rom, the baseband should be flashed. If you're going to the H812 Lineage O rom, just flash the modem.bin file from the SALT backup you do - you can always flash the baseband later if there is a problem and it is needed. Flash SuperSu after.

You're still forgetting the Thanks button, eh ... ? Hint: It's a good habit to get into when receiving help from other members.

 

[threehappypenguins]

The reason you should re-flash the same kdz, is to see if it gets the network connectivity issue solved before proceeding with anything else as you may find the problem still exists.

If you are planning to go the the LG Nougat stock rom, the baseband should be flashed. If you're going to the H812 Lineage O rom, just flash the modem.bin file from the SALT backup you do - you can always flash the baseband later if there is a problem and it is needed. Flash SuperSu after.

You're still forgetting the Thanks button, eh ... ? Hint: It's a good habit to get into when receiving help from other members.

Well, I successfully unlocked the bootloader using UsU. I flashed the the baseband package, because I figure I will first re-flash the same kdz. I also decided I will flash stock Nougat because I figure it will be more stable for my friend. Unfortunately, I only got as far as flashing the baseband package and SuperSU.zip. When I try to boot into the OS, it just hangs on the "LG Life's Good" logo forever. Should I go ahead and flash the MM kdz using LG Up new anyway? I already tried a factory reset, and it didn't make a difference.

 

[sdembiske]

Well, I successfully unlocked the bootloader using UsU. I flashed the the baseband package, because I figure I will first re-flash the same kdz. I also decided I will flash stock Nougat because I figure it will be more stable for my friend. Unfortunately, I only got as far as flashing the baseband package and SuperSU.zip. When I try to boot into the OS, it just hangs on the "LG Life's Good" logo forever. Should I go ahead and flash the MM kdz using LG Up new anyway? I already tried a factory reset, and it didn't make a difference.

If you want to hard brick your friend's phone and possibly lose a friend, sure, ignore the UsU thread OP warnings ... i.e., DO NOT flash with LGUP-NEW now that the phone is unlocked. If you're going to the stock Nougat, flash the N modem from the UsU thread. If that doesn't work, flash the MM modem from a SALT extraction of a clean Telus H81220z kdz.
Suggest you read the OP in the UsU thread fully, i.e., all of it including the FAQ's and make sure you understand it all this time.

 

[threehappypenguins]

I finally figured out why I'm so confused. Original, when you said this:

If no go, his alternatives are to (assuming he's not bootloader unlocked): try a factory reset; next, re-flash his appropriate kdz in LGUP-NEW.

I misread. I thought you said "assuming he's bootloader unlocked." So I kept thinking that in order to do ANYTHING (flash the kdz), his bootloader had to be unlocked.

I read the OP over and over, and didn't see the part about never kdz flashing with LGUp, coupled with my misunderstanding that I had to be bootloader unlocked in order to flash with lgup. But I finally found what you're talking about in the FAQ.

You can't! At least for the KDZ flashing part: not yet.
SALT will allow flashing of KDZ files with the upcoming version 4.0 but until then do not flash with lgup and do not use the LG Android internal updater --> You WILL 100% brick your device.

I realize all this is a risk to my friend's phone, it's just that I was the one who talked him into buy a used decent phone, rather than buying a new cheapo crappy phone. I just wish I didn't misread what you had said and tried flashing with LGUp *before* I bootloader unlocked.

It's been a long week.

P.S. - I wouldn't lose him as a friend over this. He is very technologically challenged, and keeps thanking me over and over for helping him with all his previous phones, for giving his wife one of our used old phones (she previously had no phone), for helping set up his network with a Tomato firmware router and OpenDNS so he can know what in the world his kids are doing online and have control over the network, etc. So if I bricked his phone, I would just buy another one used for him. He wouldn't care. He just needs a half decent, inexpensive phone to run his small business. Right now, he's just using his old phone for the time being. It's a MotoE that he's had for the last 8 years and he says, "I need to upgrade." Lol

 

[threehappypenguins]

I searched and searched for the Nougat modem (at this point, I might as well upgrade to Nougat), and this is what I found. Is this correct? Or is there another version that I need because that one isn't compatible with my phone? I also assume that the modem zip is flashable via TWRP? I see the "META-INF" folder.

This is the stock Nougat I was going to flash (with TWRP? It looks like a flashable zip). My ARB is 0. My GPT compatibility is H811.

I see in the N stock that there is already a modem.bin file. So should I first flash the stock N zip, and THEN flash the separate N modem? Also, the instructions say:

16) I just wanna flash Nougat STOCK. Are there any worry free UsU downloads for it available?
Sure: here
After flashing ensure you flash your model baseband package!
After that and while still in TWRP: Choose Reboot -> RECOVERY ! This should ensure TWRP will not be overwritten on Android boot

So, in summary:
1. Flash stock Nougat zip
2. Flash Nougat modem zip
3. Flash my model's baseband (again)?

And if none of that works:

flash the MM modem from a SALT extraction of a clean Telus H81220z kdz

?

 

[sdembiske]

I searched and searched for the Nougat modem (at this point, I might as well upgrade to Nougat), and this is what I found. Is this correct? Or is there another version that I need because that one isn't compatible with my phone? I also assume that the modem zip is flashable via TWRP? I see the "META-INF" folder.

This is the stock Nougat I was going to flash (with TWRP? It looks like a flashable zip). My ARB is 0. My GPT compatibility is H811.

I see in the N stock that there is already a modem.bin file. So should I first flash the stock N zip, and THEN flash the separate N modem? Also, the instructions say:



So, in summary:
1. Flash stock Nougat zip
2. Flash Nougat modem zip
3. Flash my model's baseband (again)?

And if none of that works:

?

Yes. Refer to FAQ #22 in the UsU thread and the Stock N report by @grantdb.

 

[deltadiesel]

The reason why you get intermittent service because the phone you found had been blacklisted by the original owner

 

[threehappypenguins]

The reason why you get intermittent service because the phone you found had been blacklisted by the original owner

It was locked to Koodo, and the original owner told me that. I called Koodo, gave the IMEI, and they gave me the Network unlock code. If it was blacklisted, wouldn't Koodo have said something?

 

[threehappypenguins]

Yes. Refer to FAQ #22 in the UsU thread and the Stock N report by @grantdb.

I flashed stock Nougat, then Nougat modem, then the H812 baseband, then rebooted directly back to TWRP. Then I booted up the phone and it was in Spanish. So I changed that to English. Then I had rebooted the phone again (adding a SIM card for testing), and it was in Spanish again, so I changed it back to English. Then I rebooted the phone again, and it was in Russian, so I changed it back to English, and also deleted all the extra keyboards which included Spanish and Russian (at least, it looked like it was Russian). Rebooted the phone a couple more times, and it stays in English.

So far, everything is working.

Thanks again for your help! Will report back if the intermittent issue comes back, or if everything continues to work well, in case anybody with the same issue is looking for a fix.

On another note, out of curiosity, I tried *#*#4636#*#* on the Phone's dial pad to open the service menu, and noticed that Phone Information is still blocked. Just curious... is that a ROM thing? Or a baseband/modem thing?

 

[sdembiske]

I flashed stock Nougat, then Nougat modem, then the H812 baseband, then rebooted directly back to TWRP. Then I booted up the phone and it was in Spanish. So I changed that to English. Then I had rebooted the phone again (adding a SIM card for testing), and it was in Spanish again, so I changed it back to English. Then I rebooted the phone again, and it was in Russian, so I changed it back to English, and also deleted all the extra keyboards which included Spanish and Russian (at least, it looked like it was Russian). Rebooted the phone a couple more times, and it stays in English.

So far, everything is working.

Thanks again for your help! Will report back if the intermittent issue comes back, or if everything continues to work well, in case anybody with the same issue is looking for a fix.

On another note, out of curiosity, I tried *#*#4636#*#* on the Phone's dial pad to open the service menu, and noticed that Phone Information is still blocked. Just curious... is that a ROM thing? Or a baseband/modem thing?

Not sure about the language issue as I haven't used the stock N rom but if it continues to hold, no problem. Make sure you do a TWRP backup when you have it where you want it.

The 'secret' menu accessed from the dial pad hasn't worked for me in AOSCP N or Lineage O so it may be a rom thing. *#546368#*812# is the dial pad code that should be tried in any event.

 

[threehappypenguins]

I just wanted to report that my friend no longer has any more issues with no service. Everything is working well. I will edit my first post to state that the problem is solved and what I did.