05-16-2007, 02:13 PM
Run the Hardware Test software that came with the System Restore CD (or DVD).
And/or run the diagnostic software of TechTool Pro (commercial) or TechTool Deluxe (included with AppleCare).
And/or run the diagnostic software of TechTool Pro (commercial) or TechTool Deluxe (included with AppleCare).