I had an issue last night. I fired up everything to work some FT8/FT4, and the rig was intermittently shutting down. I would get error messages about loss of communication with the port from Win4Icom, and oddly enough, a message from Windows Defender about how it had saved me from myself! Certainly some mixed messages!
The prime problem was the radio turning off, though. At first, I thought maybe the software was shutting it down remotely, but eliminated that. My next suspicion was that RF was getting into the laptop. That wasn’t it either!
Next, I wiggled the positive wire from the power supply to the rig … no change. Then I wiggled the black ground wire … the rig powered off! Further tugging and wiggling pulled the wire out of the terminal on the rear of the Samlex power supply. Aha!!
Evidently, the setscrew holding the wire in the terminal had loosened over time and finally, there was enough resistance to cause the voltage to drop below the minimum required to run the radio.
The moral of the story is that a simple problem can mimic a host of other problems. If your radio is shutting down, check the voltage first!
73 de Dick N4BC