My other iMac G5 rev A had its logic board replaced under warranty and I received it 2 weeks ago. Yesterday I put it to sleep, but today it is off and won´t boot. I´m wondering what might be wrong? When I got it back from the repair 2 weeks ago, it didn´t boot until it had been connected to eletricity for some time. Then there were some problems with the sleep so it just turned off, but now it just won´t boot again.