[split] star G9000 no 3G

[Athos]

Has it ever worked before?
Have you checked if youve enabled it in sim toolkit or mobile network settings? (I've missed those a few times)

Also try to go into mobile uncle tools and check indicated basebands. 3g usually only works for sim1.
Verify if the correct network frequencies are enabled.

If not, but used to be, you may need a configuration file for your phone.