Hi,
using-frdm-k64f-board-to-debug-another-kinetis-board
using-the-freescale-freedom-frdm-kl43z-to-debug-other-boards
just like the above two posts i m trying to use FRDM-K66 Board to programme/Debug my custom board with KV4x.
K66 Does not have jumper on SWD_CLK Pin as KL25Z and K64F has....SWD_SDA and SWD_CLK pins are direcly connected to Target mcu k66.

so i have decided to cut the power of k66..so by turning off it i can connect my kv4x to 10 pin connector and programme it.
for that i have cut the link of j20 jumper.

i m using j9(10 pin connector) on frdm-k66 board to program my custom board with kv4x..
custom board is powered externally...
not using 3.3v from 10 pin connector as i have cut j20.
frdm-k66f has j25 jumper for reset ...with that jumper on/off i can programme kv4x...but its not working everytime...
i even tried cutting j5(jumper connecting k20 to reset pin of k66).
i have cut the j5 track and using k20 pin direcly connect to reset pin of my custom kv4x board.
i m using MCUxpresso.