Chosen Solution
My G5 powers on, but does nothing other than run the fans - MOST of the time ! Every 10 - 15th try to turn it on, it WILL Activate and perform as designed ! - Monitor lights up, I log onto my account, ALL Programs work as designed… However, IF I put it to sleep, OR Shut it down, it goes right back to NOT Activating again…just the fans activating… PLEASE help !
First try zapping the PRAM. How do you zap the PRAM? Boot the computer and immediately hold down the following key combinations: COMMAND-OPTION-P-R.The computer will re-boot and you will hear a chime.Release the keys and allow the computer to boot normally.The PRAM has now been zapped.I usually do this three times.