When I close my Laptop (HP Pavilion g7-2318sz) and reopen it later on sometimes:
- the screen remains black
- or I see the login screen shortly but then it turns black
I press the on button several times and sometimes the login screen stays visible and I can login again. Then often the screen slightly flickers for 5-10 minutes and is ok then.
Mostly I have to full restart again because the screen remains black. All issues are gone then.
Probably an issue with my graphic card (AMD Radeon HD 7420G Discrete-Class)
It seems to be a know Ubuntu Issue. There are some hints, but no one did work: https://askubuntu.com/questions/1032633/18-04-screen-remains-blank-after-wake-up-from-suspend#:~:text=When%20your%20screen%20is%20blank,%2B%20F3%20(wait%20a%20second)