[HTC One E8] stuntgp:
Have you ever lose your phone ‘s signal due to accidentally selecting USA BAND in *#*#4636#*#* menu? If yes, this guide is for you. Thanks to [MENTION=974625]ian.anindya[/MENTION] for guidance and clues on how to restore my phone’s signal back.

Requirement:

1.	Rooted HTC One E8 phone

2.	Knowledge on how to use ADB command

3.	Software Qpst, Qxdm and Mztool

4.	A cup of coffee

This is how to do it:

1.	Download all necessary software here and extract to separate folder.

2.	Install Qpst and Qxdm.

3.	Enable USB debugging on your phone and connect it to PC. Verify with command

adb devices

It must show your device ID and must not be offline.

4.	Input command below to activate diagnostic mode

adb shell
su

If this is the first time you issue the command, check your phone. There is a prompt asking for root permission, grant it. Continue with below command

echo 1 > /sys/devices/virtual/android_usb/android0/f_diag/on

5.	Your PC will detect new hardware and install necessary drivers. If you do not have the drivers, browse to HTC Diag folder which you download together with qpst and qxdm software. If the drivers installation succeed, check your PC device manager and it will show your HTC Diagnostic Interface (in my case COM5, the value can be different on your PC).

Your phone is now ready for the fun part playing with NV items :cool:

6.	Open QPST configuration from your windows start menu. Go to Ports tab, and then add your HTC Diag com port.

7.	We need to backup current NV items in case something goes wrong. Choose start client, software download. On backup tab, select where to store .qcn file and click start and wait until finished. After finished, close QPST program.

8.	Open QXDM professional from your windows start menu. Select NV Browser in the drop down list. Since we do not connect our phone yet, the NV list is not editable.

9.	Choose option, communications. Select HTC Diag com port in the target port. If succeed now the NV browser window is editable.

Tick Dual SIM if your phone is dual SIM version. Subscription ID field will be activated.

ID 0 is for SIM 1 and ID 1 is for SIM 2.

For this purpose, we will only need to edit NV item 1877, 441, 946 and 2954.

10.	SIM 1

Make sure Dual SIM is ticked and Subscription id is 0.

We use Mztool application to define frequency parameters.

Go to Band Preference (NV Value) tab to configure GSM and WCDMA frequency that we want to put in our phone. Choose the frequency that supported by your phone.

Mine is like this

According to the picture,

Box No.1 refers to NV item 1877. Value is 73925504 (remove commas)

Box No.2 refers to NV item 441. Value is 896

Box No.3 refers to NV item 946. Value is 1128

Box No.4 referes to NV item 2954. Value is 0

All values are in Decimal

Now we need to input these values in NV browser window in Qxdm.

NV Item 1877

On column ID, find item 1877. Click Read to read current value. Take note of it, in case something goes wrong. Write the new value 73925504 under input field and click Write. Click Read again to verify.

NV Item 441

On column ID, find item 441. Click Read to read current value. Take note of it, in case something goes wrong. Write the new value 896 under input field. The value is automatically converted in to Hex.

In my case 896 in decimal is the same as 0x380 in Hex. Click Write. Click Read again to verify.

Do not touch the nam value.

NV Item 946

On column ID, find item 946. Click Read to read current value. Take note of it, in case something goes wrong. Write the new value 1128 under input field. The value is automatically converted in to Hex.

In my case 1128 in decimal is the same as 0x468 in Hex. Click Write. Click Read again to verify.

Do not touch the nam value.

NV Item 2954

On column ID, find item 2954. Click Read to read current value. Take note of it, in case something goes wrong. Write the new value 0 under input field and click Write. Click Read again to verify.

Do not touch the nam value.

Up to here, if you reboot your phone, It should get GSM/WCDMA signal on SIM 1 only. Now we are working for SIM 2.

11.	SIM 2

Dual SIM is still ticked but this time choose Subscription ID 1

Remember that SIM 2 supports only GSM (no WCDMA). So in Mztool, choose only GSM signal.

Mine is like this

According to the picture,

NV item 1877 value is 2622336

NV item 441 value is 896

NV item 946 value is 40

NV item 2954 value is 0

All values are in Decimal

Do the same procedures as SIM 1.

12.	After finished editing NV items, close Qxdm and then we have to close the diagnostic mode.

Wait around 10 seconds and then input command below to deactivate diagnostic mode

adb shell
su
echo 0 > /sys/devices/virtual/android_usb/android0/f_diag/on

13.	Reboot your phone using ADB command

adb reboot

After rebooting your phone, wait for 1 or 2 minutes and then hopefully you will get the GSM/WCDMA signal.

Later on, I will continue this guide on how to add LTE Band :)