I've been using RPi 2B for two months and it was running smoothly. Today when I connected to power supply, it does not boot. The red LED is still OFF, ACT is ON but not blinking.
I thought the problem is with the SD card, but whenever I power the board, the Broadcom IC heats up and some sound can be heard.
The sound is similar to what we hear from a power socket when the plug connected is not fitted well or from a loose connection. I don't know from which part of the sound comes. But the board heats up near the micro usb port. There's no smell of burning; one of the components got fried.