[Non F500]Downgrade nougat back to MM

[da.vandenham]

EDIT: A couple people got network problems after following this small tutorial. If that happens to you, try this: (original post by znobox)
https://forum.xda-developers.com/showpost.php?p=73685344&postcount=26

Since there were a lot of questions on how to downgrade a modified nougat back to MM, I've decided to make a poat for it.

I am not responsible in any way, just so that is cleared up.

Use REFURBISH in LGUP!!

Firstly, download this KDZ: https://mega.nz/#!H8dnXDCL!hqA-yIN3dAeuqHm-H0KltL6rfTJfb0EpVcNJYkkr0GU

If your device is a H815, you can stop here. If not:

Flash a KDZ that was created for your device since it is now a fake H815.

That's it :good:

 

[fegitoli]

Thanks for the help. I have no intention of downgrading right now, but I will when the nougat update comes out officially in Canada.

 

[UltimateDream]

.

i did that but no service or service disabled
i have h818p

 

[da.vandenham]

i did that but no service or service disabled
i have h818p

Have you flashed a H818P after the modded KDZ?

Sent from my LG-H815 using XDA Labs

 

[ZmisiS]

Have you flashed a H818P after the modded KDZ?

Sent from my LG-H815 using XDA Labs

After H815 v20o I flashed H818P v20g. Now network not working. 5 days ago I sent the device to repair.

 

[da.vandenham]

After H815 v20o I flashed H818P v20g. Now network not working. 5 days ago I sent the device to repair.

Try flashing the modem manually

Sent from my LG-H815 using XDA Labs

 

[ZmisiS]

Try flashing the modem manually

Sent from my LG-H815 using XDA Labs

Now is the device to repair. Please link for the modem. Once again I thank you for the H815 v20o.

 

[da.vandenham]

Now is the device to repair. Please link for the modem. Once again I thank you for the H815 v20o.

Here is the link for your modem: https://mega.nz/#!e5snTbaL!BYplWw8MAyNFWJ0VrrA4UZjV0Ric3-RxIRUsELZjk1c

Place it on your internal storage and flash it by executing these commands in a terminal:

dd if=/dev/zero of=/dev/block/platform/bootdevice/by-name/modem
dd if=/sdcard/modem_h818p_20g.img of=/dev/block/platform/bootdevice/by-name/modem

 

[UltimateDream]

.

Here is the link for your modem: https://mega.nz/#!e5snTbaL!BYplWw8MAyNFWJ0VrrA4UZjV0Ric3-RxIRUsELZjk1c

Place it on your internal storage and flash it by executing these commands in a terminal:

dd if=/dev/zero of=/dev/block/platform/bootdevice/by-name/modem
dd if=/sdcard/modem_h818p_20g.img of=/dev/block/platform/bootdevice/by-name/modem

i flashed h818p 20h version (GCC area)
please explain more how can i flash the modem manual using these commands by using what or how ? (sorry for my english)

 

[da.vandenham]

i flashed h818p 20h version (GCC area)
please explain more how can i flash the modem manual using these commands by using what or how ? (sorry for my english)

I have extracted this modem frm the firmware you described: https://mega.nz/#!L8VwQRJY!ESrUJlFyM_kRTNEZQaUqBiLcecQ1NgBvsbBjDz77EyU

The easiest way to flash it manually is (you need root for it):
Copy the modem IMG-file to your internal storage (don't rename it!)
Open up an ADB command line on your computer
Execute the "adb shell" command (without quotes)
Elevate the shell using the "su" command (again, no quotes)
And then run these commands:
dd if=/dev/zero of=/dev/block/platform/bootdevice/by-name/modem
dd if=/sdcard/modem_h818p_20h_gcc.img of=/dev/block/platform/bootdevice/by-name/modem
Lastly, reboot you phone and it should work.

 

[UltimateDream]

.

I have extracted this modem frm the firmware you described: https://mega.nz/#!L8VwQRJY!ESrUJlFyM_kRTNEZQaUqBiLcecQ1NgBvsbBjDz77EyU

The easiest way to flash it manually is (you need root for it):
Copy the modem IMG-file to your internal storage (don't rename it!)
Open up an ADB command line on your computer
Execute the "adb shell" command (without quotes)
Elevate the shell using the "su" command (again, no quotes)
And then run these commands:
dd if=/dev/zero of=/dev/block/platform/bootdevice/by-name/modem
dd if=/sdcard/modem_h818p_20h_gcc.img of=/dev/block/platform/bootdevice/by-name/modem
Lastly, reboot you phone and it should work.

i need root ?
there is no root for MM H818P

 

[da.vandenham]

i need root ?
there is no root for MM H818P

Sorry, I overlooked that. Without root and twrp, assuming that that isnt available either, there is no way to flash a custom modem.

Sent from my LG-H815 using XDA Labs

 

[ZmisiS]

Sorry, I overlooked that. Without root and twrp, assuming that that isnt available either, there is no way to flash a custom modem.

Sent from my LG-H815 using XDA Labs

For me on LG G4 H818P v20g, I think, not go custom modem?

 

[da.vandenham]

For me on LG G4 H818P v20g, I think, not go custom modem?

Only if you got root or TWRP, sorry mate

 

[mateus.sc]

For me on LG G4 H818P v20g, I think, not go custom modem?

Try downgrading from MM to rooted LP and then you flash the modem from the LP kdz file

 

[ZmisiS]

Try downgrading from MM to rooted LP and then you flash the modem from the LP kdz file

If I am a root device, I will lose the warranty on the device.

 

[divineBliss]

@da.vandenham,
Doesn't LGUP flash everything in the KDZ which would include modems?

 

[da.vandenham]

@da.vandenham,
Doesn't LGUP flash everything in the KDZ which would include modems?

Yes it does

Sent from my LG-H815 using XDA Labs

 

[fegitoli]

@da.vandenham
So if I wanted to downgrade from nougat, I would flash your KDZ and then stock for my variant? I really need to get the modem working on this, even if it means downgrading.

Also, since I flashed the F500L software instead of the F500K firmware, could I just edit it to work for F500L?

Any pre-modified KDZs would help a lot.

My variant is the H812 Canadian variant, which cannot be rooted, BL unlocked or have a custom recovery.

 

[da.vandenham]

It should be possible yes. Open the KDZ with a HEX editor and replace F500K with F500L. LGUP flashes the modem too so that shouldn't be a problem. As for flashing a custom modem: not possible without root or custom recovery.

Sent from my LG-H815 using XDA Labs