Currently Being ModeratedMay 4, 2012 3:42 PM (in response to CDIE)
Reset your SMC and PRAM ...
- Shut down the computer.
- Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
- Turn on the computer.
- Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
- Hold the keys down until the computer restarts and you hear the startup sound for the second time.
- Release the keys.
Currently Being ModeratedMay 5, 2012 4:15 AM (in response to CDIE)
If you have the DVD that came with your MacBook you coud insert it and restart while holding down the option key. This should give yo a choice of booting from the internal disk or the DVD. Choose the DVD and see if that works. This will give you access to Apple Hardware Test.
more info here: http://www.thexlab.com/faqs/aht.html