Turn on my macbook pro, it start for five seconds

just turn off your Macbook. wait in seconds and turn on.

You have a bad driver. Reinstall your screen driver or clear your P ram by holding the letters P and R and the control button when you boot your laptop. Hold them until it chimes and reboots.

First step would be to Reset Your Mac's SMC
The method for resetting your Mac's SMC depends on the type of Mac you have. All SMC reset instructions require shutting down your Mac first. If your Mac fails to shut down, try pressing and holding the power button until the Mac shuts down, which usually takes 10 seconds or so.

Mac portables with user-removable batteries (MacBook and most MacBook Pros):

1.Shut down your Mac.
2.Disconnect your Mac portable from its MagSafe connector.
3.Remove the battery.
4.Press and hold the power button for at least 5 seconds.
5.Release the power button.
6.Re-install the battery.
7.Reconnect the MagSafe connector.
8.Turn your Mac on.
Mac portables with non-user-removable batteries (MacBook Air and some late 2009 MacBook Pro models):

1.Shut down your Mac.
2.Connect the MagSafe power adapter to your Mac and to a power outlet.
3.On the built-in keyboard (this will not work from an external keyboard), simultaneously press and hold the left shift, control, and option keys while you press the power button. Release all keys at the same time.
4.Press the power button to start your Mac.

Mac desktops (Mac Pro, iMac, Mac mini):

1.Shut down your Mac.
2.Unplug your Mac's power cord.
3.Press and hold the Mac's power button for 15 seconds.
4.Release the power button.
5.Reconnect your Mac's power cord.
6.Wait five seconds.
7.Start your Mac by pressing the power button.

Alternative SMC reset for Mac Pro:

If you have a Mac Pro that isn't responding to the normal SMC reset as described above, you can force a manual SMC reset by using the SMC reset button located on the Mac Pro's motherboard.

1.Shut down your Mac.
2.Unplug the Mac's power cord.
3.Open the Mac Pro's side access panel.
4.Just below the Drive 4 sled and adjacent to the top PCI-e slot is a small button labeled SMC. Press and hold this button for 10 seconds.
5.Close the Mac Pro's side door.
6.Reconnect your Mac's power cord.
7.Wait five seconds.
8.Start your Mac by pressing the power button.
Now that you have reset the SMC on your Mac, it should be back to operating as you expect. If the SMC reset didn't fix your problems, you can try combining it with a PRAM reset. Although the PRAM works differently than the SMC, it can, depending on your Mac model, store a few bits of information that the SMC uses.

Assuming your computer has a built-in iSight camera - which should be all Macs made since 2006 except for the Mac Mini and Mac Pro (not MacBOOK Pro!) - your camera

a) May not be being seen by the computer. Check Apple Menu > About This Mac > More Info > USB and see if "built-in iSight" is listed in the USB Device Tree. If it is, then it may be being used by another application that uses a webcam, like Skype, iChat, or what have you. If it IS NOT detected:

b) Try resetting your SMC:

Resetting the SMC on Mac portables with a battery you can remove
Note: Learn about removing the battery on MacBook and MacBook Pro.

1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it's connected.
3. Remove the battery.
4. Press and hold the power button for 5 seconds.
5. Release the power button.
6. Reconnect the battery and MagSafe power adapter.
7. Press the power button to turn on the computer.

Resetting the SMC on portables with a battery you should not remove on your own
Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).

1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.
   Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Good luck!

Have you tried starting from the system disks that came with the computer? Put the disk into the computer and start up holding the C key down.

Press and hold the power button for about 10 seconds will power off the MacBook Pro.

You can then try turning it on again normally.

If the problem with freezing reoccurs on start up, then hold down the power button again, and turn it off. Unplug the MagSafe Power Adaptor from the MacBook and the Wall for several seconds. If the battery is removable, then remove it, wait for a few seconds and re-insert it. Plug the MacSafe back in if desired. You should now be able to start up the MacBook with no problems.

Your first recourse is to reset the power controller. Since I don't know the exact model and vintage of your MacBook Pro, I will post the reset procedure that applies to most of them.

1. If the computer is on, turn it off.
2. Disconnect the power adapter and remove the main battery.
3. Hold the power button down for five seconds, then release.
4. Install the main battery and connect the power adapter.
5. Press the power button to restart the computer.

If this does not solve your issue, your machine will need professional service.

Most likely fix is to reset the SMC.
Turn the power off, remove all peripheral cables, connect the AC power supply. Using the left-side keys, press the combination Shift-Control-Option-powerbutton ONCE. The LED on the MagSafe connector
should go off, go back to green when keys are released, and may change to orange if the battery still needs some charge. Wait five seconds, then press the power button to restart the computer.

To get a disk out of a mac hold the mouse button down whist the the machine is booting up and it should eject automatically.
WIngammon, try this.
hold Command - option P R straight after you turn your mac on. This will reset the PRAM and NVRAM. this might help.
otherwise if you have an original or copied osx install disc try booting up from that by turning on your computer, inserting the disc and then turning it off again. Give it 5-10 secs and then boot up again holding the C key. this should take you a screen similar to the login screen, you will have to choose a language. In the toolbar(top of the screen) you should go to utilities and select disc repair.
I have had this problem with my own macbook and the above things have solved it for me. However its possible that the same symptom my not be caused my the same problem.
Best of luck.
Let me know how it goes.

First remove the battery, then plug it into your AC adapter. Hold the power button for 5 seconds or until you either hear and beep or the activity light on the front of your laptop lights up. Start up normally.