Ursprünglicher Beitrag von: edwinastevens ,
I found that removing the batt and holding the power for 1 minute without power cable connecte, then reconnecting battery and starting worked for me. My issue was at first, nothing, no sound, no boot. Then after removing battery and holding power without cable connected for 5 sec I got a chime, but then nothing. Then after resetting PRAM got same thing, sound but no boot (slight screen flicker) - then the very long power hold with batt disconnected pushed it through to booting fine. Good luck!