iMac M5521 won't power on

[wagtail]

I truly feel this could just be a switch problem. If I leave my iMac on full time I have no problems with it but whenever I turn it off I cannot get it to power up again. The "on switch" glows but the computer does not turn on. You can be sure I will leave it on if someone can help me get it to power up again.
Any suggestions?

 

[oldmanmac]

Hello;
You might want to check your clock battery,If the voltage falls below 3.3 volts.then startup gets to be a bit flaky.You'll find it behind the memory access door.If you have skinny fingers you can pull it out ok. A large pair of tweezers or a hemostat makes it easier.