IMac G5 switching on/off problems

I've got a pre-Intel iMac G5, circa 2005. For a while the sleep option hasn't worked, if I put it to 'sleep' it just turns off. Now there's a problem with it turning on. It takes ages to switch it on, have to leave it for ages after turning on at the mains and then press the button up to 20 times for it to start. This is worse in the morning, after it's been off all night. I changed the battery, but it made no difference.
Any advice would be appreciated please. Thank you in advance!

c,
In addition to Klaus' excellent reference you should check your power supply and the capacitors on the logic board ala:
http://jimwarholic.com/2008/07/how-to-repair-apple-imac-g5.php
It could be capacitors on either the power supply or the logic board.
Google "removing back iMac G5" and the first return you'll get is a pdf of very good instructions on how to do that.
Report back.
Richard

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IMac G5 switching on/off problems

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