AC300 has stopped working on solar

First Post, please be gentle with me; lol I Finally got around to installing my rigid panels, five in total, 390 watts each. It’s been charging fine for the last six days but worked fine this morning. Suddenly, I’m not getting any solar input, even on the screen. The solar icon, on the screen, doesn’t go orange. I have reset the system, and it is so frustrating I’m expecting a second B300 in days.

How do you have the 5x 390W panels wired together? Most panels of that size have an open-circuit voltage of around 44-50V so you should not connect more than 3 in series and really, to be safe, not more than 2 because you want to leave some safety headroom underneath the 150V maximum because in colder weather the voltage increases.

If you have a multimeter can you measure the DC voltage on the MC4 connectors?

@pete1407u As well as the suitability of the solar panels to consider, there are also UPS settings you can check.