Beagleboard-xM not booting

Hi all,
I have a beagleboard-xM rev-B. I've been using it for almost a year.
It was working until recently when i powered it up nothing came up on
my monitor. I tried to connect with the serial connection and nothing
came up. No matter I use my 5V 2Amp power supply or the OTG usb port.
The LED on the sd card does not light up anymore. The only LED that
lights up are D5 and D14. I have no idea what happen. I have been
using it now for my senior project. I tried accessing the GPIO pin and
PWM on the expansion port. The last time it worked is when I was
testing the GPIO pin and output the signal to the oscilloscope. I got
the PWM and GPIO worked. But then, the next day. It does not boot up
any more. Anyone? Any idea whats going on with my beagle and how can i
fix it? i really need it for my project. Thanks so much guys.

Can you send a serial printout?
What revsion i sthe board?
Have you tried recreating you SD card?