ABOUT analog video port is not working

Background: Now I have a piece of AV interface 7 inch screen in my hands, I would like to use it, but according to the reference scheme to God, now still cannot be used. Specific solution steps:

  1. Reference to 123 of the post and its reference to the document, modify the configuration file. The address is as follows: Http://forum.eepw.com.cn/thread/279412/1 Http://www.cubie.cc/forum.php mod=viewthread&tid=141?
  2. Follow the steps to successfully modify the configuration file: [tv_out_dac_para] dac_used = 1 dac0_src = 4 dac1_src = 5 dac2_src = 6 dac3_src = 0

dac_used = 0 Change to 1.

`[tvout_para] tvout_used = 1 tvout_channel_num = 1

[tvin_para] tvin_used = 0 tvin_channel_num = 4

tvout_used = 0 Change to 1`

Both of the two methods are not working!

My system info:raspbian for bananapi . kernel vision :3.4.108

If the statement is not clear, or incomplete statements, please post questioning, I am a novice may have errors, please forgive me!