Hi Michael,
It seems your MBED bootloader is broken.
Please try to download the MBED firmware again.
1. download the quick start package from this link:
https://www.nxp.com/webapp/Download?colCode=TWR-KV58F220M-QSP&location=null&fpsp=1&WT_TYPE=Board%20S...
2. MBED firmware k20dx128_twr_kv58f_if_mbed_0x8000.bin can be found in folder: TWR-KV58F220M-QSP\TWR-KV58F220M_Quick Start Package\OpenSDA Application\CMSIS-DAP (Default Image)
3. Download the MBED firmware
1) power off your board
2) press the RESET button and hold on it, at the same time power on the board
You will find your board is a device named as "BOOTLOADER", then release the RESET button
3) Send file k20dx128_twr_kv58f_if_mbed_0x8000.bin to your "BOOTLOADER", and wait the sending finished.
4) power off the board and power on again
You will find your board is a device named as "MBED"
At this time, the MBED firmware is downloaded successfully, then try to send the Precompiled Examples to the MBED again.
Wish it helps you!
If you still have question, please contact me!
Have a great day,
Kerry
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