iMac Power/Startup Problem
My 3½ year-old 21.5-inch, gently used iMac, running Catalina, shutdown during normal use. The screen went black and the startup indicator bar appeared, but froze. I held in the power button to completely shutdown the device. The device however would not re-start in the normal manner by pressing the power button.
With the guidance of an Apple tech, I tried re-starting the iMac by holding down the keys P, R, CMD & OPT, and then pressing the power button. After this restart process I could hear sounds from inside the iMac and could feel the fan discharging air out the back; the screen however remained black.
Apple carry-in service is currently unavailable in my area.
Any suggestions for getting the iMac operational would be greatly appreciated.
Thank you.