Hi all, today I want to thank all the xda users with a little guide. Here I found a lot of help and I want to share my new knowledge.
Sprint and VZW M8 are CDMA devices used in the US, and based on HTC site works on these LTE bands:
EMEA: 800/900/1800/2600 MHz
Asia: 700/900/1800/2100/2600 MHz
AT&T: 700/850/AWS/1800/1900/2600 MHz
Sprint: FDD 800/1900 MHz , TDD 2600 MHz
Verizon: 700/AWS/1800/2600 MHz
TMUS: 700/AWS MHz
Is these an hardware limit? Is the VZW really made with different hardware? Some says yes, but generally I'm a donkey and I always want to try to brick my phone :laugh:
What happens when you are overseas?
You can sim unlock your device by the code supplied by US carrier, also by unlocking bootloader and installing new custom rom (GPE/cyano); but the "firmware" will restrict the bands in order to the original carrier frequencies!!!
So:
for VZW; you can call with a gsm mode but NOT use LTE with some carriers;
for Sprint: any EU sim will not be recognized at first boot! you ever going to settings and put global mode, dial *#*#4636#*#* to set GSM/LTE auto mode and AUS bands, return to settings to set LTE (very annoying issue).
for both: often GPS does not work!
SOLUTION: you can convert the CDMA device in a Global one (DO IT AT YOUR OWN RISK, Obviously)
1) First, go S-OFF
2) Unlock bootloader
3) put a non-red text firmware and install recovery in one step (choose your current modelID here
http://forum.xda-developers.com/show....php?t=2710503)
fastboot oem rebootRUU
fastboot flash zip filename_NoRedText_hboot.zip
fastboot reboot-bootloader
fastboot flash recovery filename.img
fastboot reboot
4) Boot the stock rom and make a GPS fix with any GPS Toolbox (prevention), then reboot
5) Enter in recovery, BACKUP STOCK ROM so wipe all data
6) change cid and modelID in one step
fastboot oem writecid HTC__001
fastboot reboot-bootloader
then open twrp
adb devices
adb shell
su
echo -ne '\x30\x00\x50\x00\x36\x00\x42\x00\x31\x00\x30\x00\ x30\x00\x30\x00\x30' | dd of=/dev/block/mmcblk0p5 bs=1 seek=16384
exit
adb reboot bootloader
fastboot getvar mid (or getvar all) (verify 0P6B10000 for modelid)
fastboot reboot-bootloader
7) Install any custom rom you want and enjoy a full unlocked worldwide bands device!
You can also convert in a GPE one. Probably the device also accept a firmware of a different model ID but I haven't any interest to reflash it, the phone works great!
8) If GPS does not work, restore the original rom, make a fix, reboot, wipe and reinstall custom rom; if GPS works you can delete the stock backup.
Useful sources:
http://forum.xda-developers.com/show....php?t=2708581http://forum.xda-developers.com/show....php?t=2708589Then, I'm from Italy, please report any grammar lack.
