I'm using a lenovo c40-5 with amd A8 and r5 m230, AMD chipset driver (october), the only driver version that can work is 17.4.4.
I tried to install every later version, none worked, then I install 18.12.2 (latest recommended version), after that installing, the screen goes black and I cannot use the pc. Audio, keyboard, and off button works.
If I turn off pc, then I turn on it, the screen goes black with a rainbow line at the center on the screen after boot, nothing works except off button.
I had to force disable principal module for getting a chance to uninstall that version, then install an old 17.4.4 version ... it works.
I think that new features like freesync or overclocking default would be the bug,
why did happen this?, how can I fix?