Macbook Pro Mid 2010 not powering up after smc update
I Had the same and managed to fix it using this reference:
https://discussions.apple.com/message/22024754#22024754

In summary, this is the fix:


  
  Disconnect power
  Open MBP and disconnect/remove the battery - close the back cover again
  While power is still disconnected, press and hold the power button for about 5 seconds and then while pressing and holding the power button, connect the power cable to the MBP.
  If you are lucky, your MBP will now power up with the fans blazing at 100% and keyboard backlight will be off.  This seems to be a recovery emergency mode or something.  If you MBP did not power up, try again. If your MBP does not power up then you have a different problem and don’t need to continue the following steps.
  Boot you OSX and go onto the Internet and Download the right SMC firmware version for your MBP from: http://support.apple.com/kb/HT1237
  Mount/Open the .dmg file and copy out the “Firmware” .pkg file.
  Use Pacifist or the command line to extract the content of the .pkg file.
  In my case the Apple SMC update had three models firmware in  the .pkg file and the correct one for the Mid-2010 15” model was in the folder SMC18 or something.  
  Find your correct model firmware for your MBP and copy out the following two files:  SmcFlasher.efi and 2010MBP15.smc  (the 2010MBP15.smc will be different for other MBP models)
  Copy those two files onto the OSX disk drive to a location that you can remember like /User/username/Dowloads/smc  or where ever.
  Google and search for rEFIt .  This is a boot loader app the will take over the boot process when you start up your MBP to enable you to go into a shell utility.  Read up on how to install and how to activate the refit utility.  When installed and enabled, the next time you reboot your MBP you will see the utility start up before your OSX boots.
  If you see the rEFIt utility start after you rebooted the MBP, use the arrow on your keyboard and select shell and press enter.  The shell.efi utility will start to boot in a “DOS” like window and after you see something where it wants to configure or setup something, just press ESC to cancel that.
  After the util booted, you need to first change to your internel disk with the command fs1:  that is F S ONE Colon then Enter, standing for filesystem 1
  Now you can change to the folder to where you copied the two firmware files like: 
  
  cd Users
  cd username
  cd Downloads
  cd smc
  
  There are different ways of going to the folder or find the place where you put the files.
  After finding the folder with the two files you can start the update process.
  First need to get the SMC into the right state
  SmcFlasher.efi -reset 1
  Your MBP fans should now quiet down.
  Lets Flash :-)
  SmcFlasher.efi -force -LoadApp 2010MBP15.smc -norestart
  
  
  Your SMC should now be flashing with the right version.  Once done, power down the MBP. Power the MBP back on and do a SMC reset and all should be fine now.  You can now connect the battery again and start using your MBP.