I'm working with my FRDM-K22F to develop my project and everything works fine , but suddenly it stops working . It was connected to my PC and I restart my PC when the boot process of my PC is finished I can't copy my binary file into board . I reset the board by pressing the reset button and then remove its power and the powers it again , then I tried to upgrade the board firmware with the instructions available in "developer.mbed.org" for FRDM-K22F , it tells me there isn't enough memory and it was the last things that the boards tell me . After that every time I connect the board through open sda USB port it didn't do anything , and when I connect the board through SWD with J link the board's small red LED is turned on and the and J link tell's me " Error : Error while identifying Cortex-M core . Info : Found SWD-DP with ID 0x2BA01477 . No device found on SWD . No device found at all. Selecting JTAG as default target interface." . Is there any way that I could solve this ?