User LEDs stop blinking

We are using a beaglebone black Rev A5C for our project. Mpu 6050 and ultrasonic sensor HCSR04 was interfaced at the time of operating when it showed an error and the putty session got terminated. When I plugged in again the user leds didn't turn on!!! Tried several times and also tried booting it again and powering it up with adapter as well. None of the abv worked. Only the PWR led glows for a sec at the instant when I connect the USB then no other activity happens. ( Pressing the power switch the led lights up for a sec)
Please help

Thanks

Sounds like you damaged the processor. It will need to be replaced/

http://www.elinux.org/Beagleboard:BeagleBoneBlack#Expansion_Header_Pin_Usage

Gerald