So, last night I was using my last-iteration iMac and it randomly shut off. I tried to power it back on... and it wouldn't. I then felt the back of the case and it was very hot. I figured it was an overheating issue, but now it won't turn back on. When I hold down the power button, it begins to start up and I can hear it "clicking" then it shuts down. It restarts itself, and I can hear a very low hum. Something is running inside of it, and the disc drive will spin if I put a disc in, but it's not turning on fully. I tried several different troubleshooting techniques with the main problem being nothing will appear on the monitor so a few of them are out of reach. I also tried booting to the boot disc and, again, nothing will appear on the screen. I did the one power reset which caused my fans to blow loudly and I had to, again, fix that, but... yeah. It starts up, shuts itself off, starts back up and something works but I can't tell what is whirring in there. The computer is only about six months old, but I didn't take out the Apple Care so I'm extremely frustrated, as it is well-cared for and this issue seems extremely random. Thanks in advance to anyone that can provide help.
Your iMac is warranteed for the first year so you are covered. Applecare extends that to three years but in your case you didn't need to buy it to cover this issue. Call apple and make an appointment to bring it in.
...and you can also buy AppleCare at any time during the first year, extending your cover by an additional two years. Well worth the money if you can stretch to it. But as Rick says, if it's only 6 months old you're covered.