Using zape's instruction I was able to update the firmware to NVR_K74_BL_ML_STD_V4.30.085_210409
After "ctrl+u", I had to copy and paste the command "
setenv bootcmd ';update' " to start the firmware update process.
I also have JST connectors for sale if anyone is interested. $5 shipped and I can take paypal, just send me a message.