Well after the high of loading the beta firmware and getting the SSB calibrated and working on my QMX, a downer was bound to follow. The other night I was listening to some CW and the QMX was decoding this reasonably well too. (Better than me, actually!) But I decided to connect the PC up and use the IQ output to get a waterfall display up and running using the NaP3 software. I plugged the PC in, using the USB-C connector on the radio, and then went to power it up. Nothing.... no initiated boot up sequence.... dead!
On inspection I could see that the 3.3v regulator was getting hot. I switched over to another power supply so I could check the supply voltage and current, and I could see that the there was lots of current, so much so, that the voltage protection on the power supply kicked in. There was a short. I removed the 3.3volt buck module and repeated the exercise. This time their was just a few milliamps draw on pressing the on button. I measured the resistance between the 3.3volt line and ground on the main board and this seems normal. These factors are pointing to the 3.3v buck convertor as the culprit. But I'm still not sure why this failure occurred. Was there some voltage differential between the USB-C connector and the 12 volt supply? Not sure.
Be assured an update will follow.