While attempting to upgrade the Multiplus firmware the step by step instructions say to unplug the cerbo gx and ve bus bms, and turn off the manual sw on the inverter. After connecting the mk3 into the cerbo gx port then turn rocker sw back on. At this point the inverter does not power up even though the 12v power supply is still connected. What am I missing ? How do I cycle the inverter and should it power up without the bms?
I feel kinda silly now. Thanks