Mac book will not turn on... it was working fine earlier in the d

Hi There,
I hate to say it, but you might have one the MacBooks whose battery has swelled, and interferes with using the click function of the keyboard.
If that is the case, you can take your laptop to an Apple Store and quietly, but sternly, raise hell with them so that they will replace your battery free of charge.
Hope this helps & good luck!

Hi
Try clearing your browser cache and delete cookies. As there are different methods for different browsers I cannot explain exactly how to do this.

Hope this help

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.

Resetting the PRAM may do the trick:
You reset the PRAM by rebooting a Mac and then immediately hold down the Command+Option+P+R keys, you will then hear the Mac reboot sound again, signifying your PRAM has been reset. You must hit the key combination before the grey screen appears otherwise it won't work.

you've tried rebooting, you've reset the PRAM, you've done it all, but your Mac is still behaving strangely. What next? In certain circumstances, resetting your Mac's System Management Controller (SMC) can be a solution. This is sometimes necessary to restore normal lower level system functionality to your Mac.

Here's how to reset the SMC on any type of Mac (and any version of OS X) and the type of problems that it may resolve.
When & Why Reset SMC on a Mac? Some Common Hardware Reasons

Typically it's power and hardware related issues that can be helped or resolved by resetting a Mac SMC, particularly if you're having these types of problems:

* Issues with your Mac's cooling fans and fan management: fans run constantly at high speed, fans run high despite low CPU usage and adequate ventilation, fans not working at all, etc

* Power management and battery problems: Mac isn't turning on, sleep isn't working, random shutdowns and reboots, battery isn't charging, Mac won't wake from sleep etc

* Light problems and improper lighting management: battery indicator lights aren't working, display backlighting isn't adjusting to ambient light changes, keyboard backlights not working, etc

* Video and external displays not working: display brightness functionality not working properly, target video mode isn't working properly, external display isn't working, etc

* General performance and functionality problems: abnormally sluggish behavior despite no CPU or disk usage, external ports not working, airport & bluetooth aren't showing up, external devices are not being found, etc

So now that you've concluded you need to reset your SMC (Note that the SMC is on Intel Mac's only), here's how to do it on MacBook's, MacBook Pro's, iMac's, Mac Mini's, and Mac Pro's. Notice that the reset instructions are different for MacBook and MacBook Pro's if you have an internal or detachable battery.
Reset SMC of a MacBook Air, MacBook Pro Retina, or MacBook Pro's with an internal non-removable battery

This is how to reset SMC on most modern Mac laptops:

Shutdown your MacBook Air / MacBook Pro
Connect the power adapter to your Mac
On the MacBook/Pro's keyboard, hold down the Shift+Control+Option keys and the Power button at the same time
Release all keys and the power button at the same time
Boot your Mac as usual

Here's the key sequence to hold down:

Reset the SMC of a MacBook Air or Retina MacBook Pro

Do keep in mind that by resetting the SMC you will lose power specific settings, like the time it takes to sleep a Mac and other customizations to power settings. No big deal, but if you have made many changes to your hardware behavior you will want to adjust stuff like sleep behavior again.
Reset SMC of an iMac, Mac Pro, Mac Mini

Resetting SMC is different for non-portable Macs:

Shut down your Mac
Disconnect the power cord
Press and hold the Mac's power button for 5 seconds
Release the button
Reattach the power cables and boot the Mac as usual

Reset the SMC of a MacBook or MacBook Pro's with detachable batteries

mac reset the smc Older MacBook laptops with a removable battery can reset SMC with the following approach:

Shutdown the MacBook/Pro and remove the battery
Disconnect the power adapter, hold the Power Key for 10 seconds
Release the power key and reconnect your battery and power adapter
Turn your Mac on
Let boot as usual

Hopefully that will clear up your problems, if not it might be worth a visit to the Apple Store or a certified repair center.

Happy New Year,
Kerry

Unplug it, remove the battery. Once it shuts down, replace the battery, plug it back in and start it up.

To have a try like this,put off the power connect wire,and took off the laptop battery for Makbook,it must be shutter down.Then restart it again! Good luck.

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!

i think that the battery has had its last run. Plus the computer want into safe mode and froze and force shut down. this is not bad. this just means you have o get a new battery cord. i have had the same issue.
CATION: charging again may result in sizzling or fire.
i had my charger start to sizzle

Which macbook do you have?

Can you describe the beeping pattern?

is the battery fully charged? try plugging it in then press the power button again.