DIY USB Programming Cable
The programming cable is super easy to DIY. You just need a spare USB cable and an RJ45 plug. Note that Kenwood, like Motorola, uses reverse pin numbering.
The view below is looking into the mic jack on the control head.
There have been some cases of these radios getting stuck in boot loops. The radio(s) will power up, show the boot screen, and then power up. The process will repeat as long as power is applied.
If you encounter your NX5000-series mobile is bootlooping, first try re-seating the ribbon cable(s) that connect the brick to the head. This has been known to solve random boot loops in several separate cases.
The following procedure comes from a tech at Kenwood:
Power on the radio(s) while holding the menu button. This should bring up the transceiver information screen. If the radio(s) come on and stay powered on this screen, you will be able to read them with KPG-D1. Once they've been read, they should reset to the default channel/zone and no longer be stuck in a bootloop.