My iMac desk top turned off by itself and it will not turn back on again. Anyway to trouble shoot?

I have a 27" iMac desktop. I just updated Big Sur a yesterday. It was on all day and was on when I got home. Then when I went to do some work I noticed the computer display is black. I tried to reboot but the computer will not boot up. I held the on/off button for ten seconds to make sure it is off. Then I hit the on/off button again. I can hear a faint click coming from the back of the computer but nothing on the display no matter how long I wait. Is there anyway I can do some trouble shooting as a user?