On Power up USR0 and USR1(D6, D7) LEDs are not glowing

I am beginner in Beagle board. I just gone through the beginners page
"http://elinux.org/BeagleBoardBeginners" and as per the article after
power up i should get D6 and D7 glowing after some time.

i powered up the device using otg connector. power LED glows and PMU
Stat LED start blinking (appox once in 3 sec) and no other LED glows.

Afterwards i also connected serial cable (cable is as per the
specification given in various beagleboard pages), but nothing appears
on the terminal.(I am using proper baud rates and other config

please let me know how i can proceed