I have installed on it:
V987 Android 4.2.1 V2.0MOD by BM, after that the 3rd and 4th version also. Now I have ROM BM 4. Noone solved my problem.
The phone is manufactured August 2013. It works good with 3G also, modem works in mode H or H+. I have tried 3 networks in my country and it works, anyway there is a network in my country which has voice/messages disabled and has roaming for data, the network is only for data service, no voice/message, this network works on my huawei and it works also on another v987 (probably version with another "baseband", I guess)
My V987 cannot connect to the network.
I have made a log from logcat
logcat -b radio -v threadtime *:V
There is that log:
The radio had been disabled, I had enabled it, the v987 tried to connect and failed
The network is called "FullName is Aero2", numeric "mccmnc = 26017, pnn = Aero2'
There is a log from connecting to the network
[GsmSST0] long: Plus short: Plus numeric: 26001
full success, and the phone can works on 3g h+ mode, above 9mbit/s works
Ask any question if you want.
PS I know that this is advanced problem but I cannot post on proper part of this forum for developers.