Today, after I did a software update on my MBP, I let it restart to complete it.After about 15 minutes I went to check if it had finished and realized there was something wrong. My screen was black,as if the MBP was turned off but the hard drive was working and doing the sound it always did.I turned it off by using the turn on/off button and then it turned off.After turning it on again it didn't do the start up chime and again the hard drive was working and the screen was black. Also the buttons aren't lighted up nor is the Apple logo at the back off the screen.I tried pressing my caps lock key but the green light didn't turn on. I've tried reseting the SMC but nothing happened. I searched the Apple Troubleshooting site but didn't find anything that could help me.Any thoughts/solutions/links that may help me?Should I take the MBP to an authorized service provider? Thanks in advance for your help.