3 months old MacBook Pro crashed My MacBook Pro is just 3 months old. It is 13 inch running i5 processor. Today I was working on Eclipse and connected one end of USB cable to the MacBook. I was about to connect other end of USB cable to my Android phone when the MacBook crashed suddenly. 

MacBook was running on battery at the time of crash, I tried pressing power buttons many times but it didn't help. Around 20 minutes before crashing I had checked battery and it said that 2 hours are remaining. I connected power adapter and it is showing very dim green light (as compared to bright green light that is shown when charging). 

What can be the problem here?
Since your MacBook Pro is only 3 months old, it is under warranty. Take it to an Apple Store or other Apple authorized repair center immediately and let them diagnose and fix the problem.

You might have a faulty Mac motherboard, or you might have a faulty MagSafe power adapter, or, worse, the electrical current in the house where you plug in the power adapter may have substandard "dirty" power that is preventing the power adapter from properly powering the computer.

But since it is under warranty, the authorized Apple repair people will diagnose the problem for you. If it is the fault of Apple equipment, they should repair it for you at no charge.