Hi! I tried installing an app but it said that I should update to the newest macOS. I launched an update but midway it turned down my iMac and now I can't turn it on again. I push the button, it shows my the apple logo for couple of seconds and powers down again. I tried rebooting, I tried pulling off the cable and I tried holding command+option+p+r buttons but nothing works. Has anyone stumbled on this issue and knows a way out?
