MacBook Pro won't go to sleep when lid is closed I have a Late 2011 MacBook Pro and I just got it back from the repair shop (mainboard was swapped). I immediately installed OS X El Capitan (before it was Yosemite) and found that when I closed the lid, the Mac would not go to sleep anymore. Even testing in other user's accounts and after restarting, resetting NVRAM and SMC and even booting from a different hard disk (with OS X Lion installed), it won't go to sleep and also the little LED on the right will not light up, neither while booting nor when I close the lid. Running pmset -g assertions in Terminal gave this output: 

Assertion status system-wide:

   BackgroundTask                 1

   ApplePushServiceTask           0

   UserIsActive                   1

   PreventUserIdleDisplaySleep    0

   PreventSystemSleep             1

   ExternalMedia                  0

   PreventUserIdleSystemSleep     0

   NetworkClientActive            0

Listed by owning process:

   pid 54(configd): [0x00000054000701d1] 00:02:13 DenySystemSleep named: "InternetSharingPreferencePlugin" 
   pid 102(hidd): [0x0000001e000901ba] 
00:03:07 UserIsActive named: "com.apple.iohideventsystem.queue.tickle" 
    Timeout will fire in 894 secs 
Action=TimeoutActionRelease
   pid 44(UserEventAgent): [0x00000030000b01cd] 
00:02:48 BackgroundTask named: "com.apple.mds.0" 
    Created for PID: 64. 
   pid 44(UserEventAgent): [0x00000006000b0137]
 00:03:30 BackgroundTask named: "com.apple.metadata.mds.power" 
    Created for PID: 64. 
Kernel Assertions: 0x100=MAGICWAKE
   id=501  level=255 0x100=MAGICWAKE mod=01.01.70, 
07:30 description=en0 owner=en0
Idle sleep preventers: IODisplayWrangler


I have prevented bluetooth devices from waking the Mac, but otherwise I am not sure what to do. Could it be a hardware issue caused by the replacement of the motherboard?
This is looking like a hardware problem. It's possible that the repair shop may have hooked it up incorrectly (even professionals make mistakes) such that the lid closing doesn't register, or the connection may have been knocked out of place.