If your MacBook Pro won't turn on, I recommend checking out the following article:
Troubleshooting: My computer won't turn on
I especially recommend step 4, which links to this article:
Intel-based Macs: Resetting the System Management Controller (SMC)
Resetting the SMC, as suggested by ariel s, certainly won't hurt and is an easy solution to try. However, my money would be on a hardware issue, probably with the charger itself. If the SMC reset doesn't help, make an appointment at the Genius Bar at your nearest Apple Store, then take the machine and the charger for the tech to look at.