MacBook Pro Suddenly Goes to Sleep and Will Not Wake Up I have 15-inch, Mid 2010 MacBook Pro running Mac OS X Lion 10.7.5.

It will occasionally (every other day) without warning go to sleep. I can see the sleep indicator on, but otherwise it is completely unresponsive to the keyboard or mouse pad. Pressing cap locks will not even show the green light.

I have noticed this happening


During boot up (so it is not a hot battery issue).
Rendering a PDF 
Ejecting an external disk


These symptoms will happen when the laptop is powered by the battery or from the wall outlet.

Ultimately, I have to press the power button for several seconds in order to do a hard reboot.

Are there any suggestions on how to diagnose and remedy issue?

Edit per request from Graham:

Time stamp                Domain                Message                                                                     Duration    Delay     
==========                ======                =======                                                                     ========    =====     
UUID: DC..
1/5/14 5:50:53 PM MST    sleep                  Clamshell Sleep: Using BATT (Charge:94%)                                    12544 secs
1/5/14 9:19:57 PM MST    wake                   Wake due to EC LID0: Using AC (Charge:100%)                                 1153 secs 
1/5/14 9:19:57 PM MST    hibernatestats         hibmode=3 standbydelay=0                                                                wr=21014 ms     
Sleep/Wakes since boot:14   Dark Wake Count in this sleep cycle:0

Time stamp                Domain                Message                                                                     Duration    Delay     
==========                ======                =======                                                                     ========    =====     
UUID: B6..
1/5/14 9:39:10 PM MST    sleep                  Clamshell Sleep: Using AC (Charge:100%)                                     2502 secs 
1/5/14 10:20:52 PM MST   wake                   Wake due to EC LID0 EHC2: Using BATT (Charge:99%)                                     
1/5/14 10:20:52 PM MST   hibernatestats         hibmode=3 standbydelay=0                                                                wr=18980 ms     
Sleep/Wakes since boot:15   Dark Wake Count in this sleep cycle:0

Time stamp                Domain                Message                                                                     Duration    Delay     
==========                ======                =======                                                                     ========    =====     
UUID: 9A..
1/8/14 11:01:05 PM MST   sleep                  Clamshell Sleep: Using BATT (Charge:96%)                                    32820 secs
1/9/14 8:08:05 AM MST    wake                   Wake due to EC LID0: Using BATT (Charge:90%)                                          
Sleep/Wakes since boot:1   Dark Wake Count in this sleep cycle:0

Time stamp                Domain                Message                                                                     Duration    Delay     
==========                ======                =======                                                                     ========    =====     
UUID: 49...
1/9/14 9:51:08 PM MST    sleep                  Clamshell Sleep: Using BATT (Charge:95%)                                    9838 secs 
1/10/14 12:35:06 AM MST  wake                   Wake due to EC LID0: Using BATT (Charge:93%)
I had the same issue.. I updated to 10.9.3 and this solved my issue