1. Frequency lock through QXDM
QXDM工具View->New->Common->NV Browser:
NV ( NonVoliatile ) parameter is the non-volatile parameter stored on the terminal, can view the NV Browser to view and modify. This information is solidified inside the terminal by the manufacturer and generally does not allow users to modify it. At the same time, the terminal can be operated Offline (restart after power failure) through NV Browser .
Among them, 06828 LTE BCconfig can configure the band information supported by the terminal, and read the value of this item (the default read is decimal) and convert it into binary. From the last bit, each bit indicates whether a band is supported (0 means not supported, 1 Show support) . If you need to modify a band that does not support it, change the 1 of the corresponding band to 0 , and then convert it to decimal, write and restart, the corresponding band is not supported .
For example, the capability information of a terminal is
2070174236885 = 0x1E2000000D5 = 0b11110001000000000000000000000000011010101
You can see that the terminal supports BAND1, 3, 5, 7, 8, 34, 38, 39, 40, 41.
If you want to change to not support band3 and band34, then
0b11110000000000000000000000000000011010001 = 0x1E0000000D1 = 2061584302289
2. Frequency lock through QPST
For mobile phones such as Mi 8, Mi MIX3, after QPST is connected to the mobile phone, access the mobile phone driver files through QPST->EFS Explorer.
To lock the frequency, you need to modify the carrier_policy.xml and carrier_policy.xml_Subscription01 files in the policyman path. The carrier_policy.xml file is the configuration for SIM1, and carrier_policy.xml_Subscription01 is the configuration for SIM2.
Find the rf_band_list name="rf_bands_home" part, modify the band indicated by <include>, where 2 7 33 37 38 39 40 means bands 3, 8, 34, 38, 39, 40, 41, which is the band indicated by <include> Plus one.
If you want to modify it to not support BAND3, 8, 34, then change it to "<include> 37 38 39 40 </include>", which means that only BAND38, 39, 40, 41 are supported.
Note: You need to restart your phone after modification, and you need to reconfigure each time you change the SIM card.
3. VIVO phone lock band
*#*#9955#*#*
4. VIVO mobile phone capture QXDM log
Phone dialing--*#558#--Quality test--Check the debug port