How to open Letv mobile phone the signal of CDMA？

The preparatory work：Letv X800 or X900
EUI version：5.0.0.19E（Experience）or above

First step :
Click the phone icon.

Second step:
Enter code * # 9439 # # * *

Third step:
Options: Enable CDMA.

The last step:
Wait for a signal search.