I was able to replace the power supply, but it appears there is something else wrong with my iMac. It started normally, but slower. After I entered my password, it loaded very slowly. When the progress bar completed, it went to a pure white screen. I left it for an hour or so and decided to shut it down with the power button. This time nothing happened when the progress bar finished. I left it and went to bed. The next morning, I woke it up and it was asking for my password again. Screensaver. My computer had the pages I was viewing when the power supply gave out. Everything was slow to respond, but I eventually got the pages closed. The computer won’t respond to my commands for the most part. I’m not able to open any of the programs. Safari, mail, etc… I left a question in the forum.