This can be an operating system change implementing low-power sleep when the system is idle. Often it doesn't happen during initial development. Hopefully the dish OS is shared with the military and commercial users, where this can be more important than it is for most residential use.

There's a trick I learned while developing embedded devices. Connect an oscilloscope across a current shunt feeding the device. You will generally see the CPU scheduling clock tick at 100 Hz or so, and other periodic power drains.

    Thanks

    Bruce