Locate the Problem

• Some problems that appear to be display issues are actually occurring elsewhere. Here are three common problems:
  
  • Symptom: The monitor is blank on startup.
  
  The problem may be in your boot-up sequence. Restart the computer holding down "command-option-S"; if you see white text appearing on screen, then the monitor is fine, but you need to troubleshoot your Mac OS X installation.
  
  Look closely at the monitor with a bright light behind you; can you see anything on screen? If so, your back light is blown or turned all the way down. Try holding down "F2," and then "Function-F2," to see if you can turn it back on.
  
  Otherwise, if you can hear the normal system noises (hard drive, internal fan, startup chime), you may have a dead monitor. See below for troubleshooting.
  
  • Symptom: The image on monitor is very large.
  
  This isn't a display problem, it's a software problem. You may have accidentally used Universal Access Zoom. Try holding down the "Control" key while scrolling down with your mouse wheel. Then turn this feature off in System Preferences > Universal Access > Seeing > Zoom.
  
  You may have set a lower-screen resolution. You can fix this in System Preferences > Displays > Resolutions. If this happens every time you start up, you may need to replace your battery. (You'll likely also see error messages about your date being set too early.)
  
  • Symptom: The monitor is a kaleidoscope of colors or has permanent vertical lines on screen.
  
  Bad news: You have a broken monitor cable. See below for troubleshooting.
  
  

Working Around a Dead Monitor

• Unfortunately, a broken internal PowerBook monitor is frequently not worth fixing; the cost of a new internal display will be higher than purchasing a new Mac laptop. These workarounds are designed for emergency laptop use and to retrieve your data for transfer to your next computer.
  
  • Hook up an external monitor to your PowerBook and reboot. You will see one of two things on the external monitor: Either it will mirror your internal display, allowing you to use the computer normally, or it will show you a secondary desktop. To turn on mirroring when you can't see the primary display, close the PowerBook lid and wake it up with an external keyboard. The external display will be used as the primary. Your first step: make a complete backup of your hard drive, which you'll use to migrate to your next computer.
  
  • If the external monitor is also blank, then the problem is deeper than your monitor; your PowerBook is no longer putting out a display signal at all. In this case, shut down your PowerBook. Your next step will be to remove your hard drive, and make sure nothing happens to your data until you're ready to migrate (especially if you don't have a recent backup).
  
  Try all of the above at an Apple Store, if one is available to you. The store will usually loan you equipment for your tests (such as monitors and keyboards), and "Geniuses" can walk you through troubleshooting so you can retrieve your data if your monitor is permanently damaged.