Mac book only shows apple logo when turned on

This could be an issue where you may have a few Startup items in your StartupItems folder in your System Library which may be affecting your Macbook's startup.

So I recommend you boot your Mac into Safe Mode to see if you can't remove a possible folder(s) that may be affecting your Mac's start up function.

Try these steps:

-SAFE BOOT MODE-
• Reboot your Mac
• Upon restarting your Mac, press the Shift key.

• Hold the Shift key until you see a White Screen with Gray Apple icon and eventually a spinning gear.
• When you see the Spinning gear, release the Shift key.

• Allow the Mac to continue booting up. Also this may take a little while.
(NOTE: this may take anywhere from 5 to 15 minutes to load to the Safe mode screen depending on the performance of your Mac, but if it exceeds this time, shutdown your Mac and try just once more. It may have just frozen up the first time around for you.)

• You are going to enter the Safe Mode (which looks like your main desktop environment the only difference is certain start up items are disabled.)

• Once within the Desktop in Safe Mode
• From the Finder Menu, click Go> Go to Folder
• Type in this line: /System/Library/StartupItems

• This path, is going to take you to the System Library folder which has all of your Mac OS X Startupitems.

• Remove all of those folders to the Trash.

*Reboot your Mac normally and see if you can access your normal User desktop environment.
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Let me know if this helps!

Regards,

-Mactechtrainer