Recently the AC input plug to which my MultiPlus Compact is connected stopped working for a reason that I have not yet identified. The inverter continued to work as long as the batteries (solar-charged) had energy to supply.
I connected the MultiPlus to another working AC input plug, and the situation seems back to normal except for one thing: when I connect the RJ45 ethernet cable to the MK2 USB interface, the Multiplus turns off (all LEDs turn blank and I can hear a relay switch) as if I had switched it off with the button. The moment I unplug the network cable, the MultiPlus turns back on immediately by itself.
This happens even when the MK2 is to connected to a USB port.
I tried replacing the RJ45 cable, the problem remains.
This does not happen if I connect the RJ45 cable to the Ethernet port of a computer.
I opened the MK2, it looks brand new with no trace of anything melt or burnt, no loose connection. Likewise, I see nothing worrying when I open the front of the Multiplus.
What could cause such a behaviour and what can I do to identify the root of the problem?
I suspect the problem lies in the Multiplus rather than the MK2, because it would be an odd coincidence that the MK2 stops working just after the recent events (it was connected when the AC failure happened).
Any idea?