Chosen Solution
This iMac is under 3 years old and have never been serviced. The black screen issue started when I tried waking it up from sleep. When I tried to restart it I can’t get the screen to show anything. I’ve tried resetting the NVRAM (the second chime is like coming from a tiny speaker, is this normal) and the SMC. When i tried to run diagnostics that’s the time the fan started getting loud
Resetting the SMC will sometimes cause the fans to race for a short time until the system fully boots up. Are you able to see any light from your display when you start your system? Try taking a flashlight held against the screen to see if you can see your desktop and its icons, are you able to see them?
