blank screen on start , power but no chime
had this problem a while back , and got a pro to fix it , he said it was the cmos or pram in a mac .
all was fine till i left it on over night , it wouldn't wake up from sleep so shut down and the same problem came back .
tried reseting the pram by disconnecting the pram battery and unplugging machine for two hours .
still didn't work then i took out one of the ram chips and tried and again , this time i got a chime but still a blank screen .
so put both ram chip backs and went back to original problem
Is this a good question?