My friend has a multiplus 24/3000/70-50. The Main switch is not working at all. If i connect shore power to the multiplus, it starts charging and powering output 1 and 2. It dont mather if the switch is on, off ore charger only. The problem is that the inverter function is not working. If I disconect shore power, the multiplus turn of, and inverter is not starting. Anyone has any solution on this problem with main switch?