[Nexus 5 General] Guiper:
Hi,

Credits to the user Azlun who initially posted the solution on the gfan foruns (In chinese).

I'm just creating a thread here in xda to raise attention for more developers and other people which might be interested.

Azlun managed to enable some extra bands in the Nexus 5 phones. Since a lot of people import the phones, relocate or travel, this can be useful for people.

I'm not responsible if you burn your phone or make a brick from it. It has been confirmed to work for a couple of users without any downsides.

Before making any changes, please make sure you do an EFS Backup (preferentially using TWRP) as well as a backup of your original NV in a qcn format details using the QPST software download tool (instructions bellow).

This hack will be maintained even if you flash any roms or OTAs, unless you restore your EFS partition from a backup or the original qcn via the QPST software download tool.

User Xtachix put together the basis for this tutorial! Thanks! (Still under development)

Prerequisites:

First thing is first, you will need to download the file available (Will update later today).

Windows

Google latest usb driver found in: latest google usb driver

adb binaries installed. Google for it, a lot of resources.

QPST_2.7.411

QXDM-3.12.714

lg_android_31010.exe for diag drivers

Walkthrough/guide for adding Band 3 and 8 to D820 and 2 and 4 to the D821. Make sure you select the correct file.

Don't cross flash, as we don't know what might happen!

Preparation Windows

Install the LG Diag Drivers executing the file lg_android_31010.exe

Install the QPST tool, QPST_2.7.411

QXDM is optional and used to debug / confirm the mod has been done.

Preparation Nexus 5

Install the app Nexus 5 Field Test mode

Make sure you have the phone rooted

Enable usb debugging

Now you need to obtain your SPC code. For doing it open Nexus 5 Field Test Mode App, got to settings (view), then LTE, and click on edit. At the same time use logcat to get the SPC code

adb shell
logcat -d | grep "commandId\ 200"

You should get something like

D/LG_SVC_ITEMS(18638): getCommands commandId 200 = ******-END

Where the "*" values are the digits to your SPC.

NOTE YOUR SPC CODE DOWN!!

Now let's make sure that your NV becomes writable, go back into the Field Test Application, input the SPC code from above, and make sure the settings look like the picture bellow. Important is to disable band 26 and set priority of 41 to 0. (Don't worry band 26 will become available again after flashing the qcn).

After setting it, click back and your phone will reboot. This is expected

Make sure the kernel you are using supports DIAG mode. If you are not sure, reboot your phone into bootloader mode and boot using fastboot this kernel (even though it says 4.4.2, it will work for 4.4.4).

fastboot boot 4.4.2_diag_BOOT.img

Reboot phone into the ROM and keep it connected to the computer.

Executing the hack

Now you have to use ADB through a pc, to get you phone into DIAG mode

adb shell
su
setprop sys.usb.config diag,adb

your device will disconnect and reconnect to become a COM port device. that's what you want.

Open device manager and check the COM port of the nexus, note it down.

Open your recently installed QPST software in windows. Windows 7/8/8.1 make sure you execute it as admin!

Select the ports tab and add a new port. the COM port that you noted down is what you want to select on this window. Click ok.

Now you will be back at the "ports" tab with your nexus 5 COM port. Up in the menus select "Start Clients" and select Software Download.

To be safe let's do a backup. Select the backup tab and perform a backup of your initial NV status to any file in a safe location on your computer. It may take around 5 minutes to perform the full backup.

Select the Restore tab.

Now select the correct QCN file, attached on this post.

D820_RF_LTE_ENABLE_B3_B8_RemovedSameItem_NOT_Overrided.qcn - Adds LTE band 3 and 8 to the D820. (Band 8 not tested, let us know if it works)

D821_RF_LTE_ENABLE_B2_B4_Filtered_RemovedSameItem_NOT Overrided.qcn- Adds LTE bands 2 and 4 to the D821. (Band 4 not tested, let us know if it works). File updated due to a minor typo.

for your SPC code, use what you have obtained above.

Allow phone/file ESN mismatch" has to be ticked.

Click Start. After a few seconds you will see and Error .

Errors: Could not Reset the Phone. Communication Errors Occurred. Do not panic, this means you did everything correctly :)

Reboot your phone.

You should the extra bands working. Let us know if works, since we are still experimenting. We are specially looking for feedback on bands 4 for the D821 and band 8 for D820.

There is no easy way to confirm if the new bands are working or not without connecting to them.

Using QXDM tool you can confirm the mod has been applied, but if you are not in an area with LTE you cannot confirm it works.

Some debug steps is to make sure your Preferred Network mode is selected as "LTE (recommended)" and your SIM Card has 4G enabled.

To disable the hack, just restore the original EFS (preferentially)and/or the qcn backup.

For more details take a look at the service manuals available here. Interesting sections are 3.5 and section 5 the RF Block.

Keep in mind that we can't enable extra bands which are not available in any of the version of the phones.

Also D820 cannot work on B20 (HW is different), neither B7 (HW is not there at all).