Chosen Solution
My iMac A1311 / EMC2428 was powering on intermittently and stopped working completely. Tests showed that the power switch was faulty. Before, I found that the unit case, especially near the PSU was getting pretty hot so initially I thought the PSU was bad. As I couldn’t get an OEM replacement switch I installed a ’normally open’ switch. This switch worked perfectly, but notice that when I install the glass panel the unit will not boot. Only when the panel is off it will boot successfully. Any suggestions on the possible cause / fix will be greatly appreciated.
Here’s a useful Question on how to fix the power button: Power button loose/no response
