Apple MacBook (13-inch, Aluminum, Late 2008) - Manual (Page 55)

Chapter 4 Problem, Meet Solution 55
 If the problem persists, return the computer to its factory settings by disconnecting
the power adapter, removing the battery, and holding down the power (®) button
for at least 5 seconds.
 If you recently installed additional memory, make sure that it is correctly installed and
is compatible with your computer. See whether removing it and reinstalling the old
memory allows the computer to start up (see page 42).
 Press the power (®) button and immediately hold down the Command (x), Option,
P, and R keys simultaneously until you hear the startup sound a second time. This
resets the parameter RAM (PRAM).
 If you still can’t start up your MacBook, see “Learning More, Service, and Support” on
page 63 for information about contacting Apple for service.
If the screen suddenly goes black or your MacBook freezes
Try restarting your MacBook.
1 Unplug any devices that are connected to your MacBook, except the power adapter.
2 Press the power (®) button to restart the system.
3 Let the battery charge to at least 10 percent before plugging in any external devices
and resuming your work.
To see how much the battery has charged, look at the Battery ( ) status icon in the
menu bar.
The screen might also darken if you have energy saver features set for the battery.