Will not turn on
Hi my imac worked perfectly for 6 years, went to switch on yesterday and nothing at all, no lights or noise. I can hear a clicking sound from the rear !!
It could be a couple different things, but my first thought is a failed power supply. It could be shorted out due to a component failure, which would certainly prevent any other components from starting up and could cause a clicking sound.
Check the power supply itself using the guide here.
While following the steps to get at it, keep an eye out for any other signs of damage or problems (discoloration of the logic board, scorch marks, any burnt smell, or anything obvious). It's unlikely, but I wouldn't dismiss the possibility.
If you don't have the tools, you can get them through the Parts & Tools section of the site. The ones you need will be at the beginning of the guide (you can click on them to access their respective pages).
I hope this helps!
To repeat the comment above, here's a link to a similar thread on the same machine. Thanks to mayer for this bit of diagnostic advice:
Did you get any solution to that problem?
My 2118 has absolutely the same symptoms including clicking at the rear.
Could that be caused by the internal battery had gone flat?