I have a new sunyboy grid tie that can hook to the grid and feed the grid . It only connects at low voltage . if i disconnect at 4000 watt it wont reconnect and displays error 3501. I isolate the two strings one at a time and still the same error . That leads me to think the issue is something both strings have in common . That would be the combiner or the inverter . I swapped out the combiner. I am down to the inverter . any ideas thank you
