i used to be able to use standby on my pc and it would work now it just sits there frozen like i have to  manually turn pc  off any ideas why its doing this  ty

My father recently had a similar problem. SOmetimes it would take 20 minutes or longer to come out of standby. Then suddenly a few times when he booted up the PC, the screen was completely black. He would reboot a few times until it would work. The problem turned out to be his monitor. The monitor was either going bad or the cable connection of the monitor was going bad. I swapped out a new monitor, and that solved his problem.

I should note that before we swapped out monitors, I also went into his power settings in Windows and changed them around to see if that would help. In his case, it didn't.