my mac pro wont start up - power cord is attached and green, start sounds are made but screen remains black
battery checks good and I have used the power cord at different outlets
Problems related to startup, unexpected system sleep, shutdown, lights or fans call for an SMC reset:
Resetting the System Management Controller (SMC)
Resetting the SMC on Mac portables with a battery you can remove
- Shut down the computer.
- Disconnect the MagSafe power adapter from the computer, if it's connected.
- Remove the battery (to remove the battery - click here: MacBook or MacBook Pro).
- Press and hold the power button for 5 seconds.
- Release the power button.
- Reconnect the battery and MagSafe power adapter.
- Press the power button to turn on the computer.
Resetting the SMC on portables with a battery you should not remove on your own
- Shut down the computer.
- Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
- On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
- Release all the keys and the power button at the same time.
- Press the power button to turn on the computer.