After fixing error code 09 (DC bus soft start failed) by replacing a few MOSFETs and IGBTs, the solar inverter stopped detecting solar panels. I checked the voltage at the fuse (before and after) and at the end of the cable. In all cases, it read 400 V. But Immediately after connecting the cables to the inverter, the voltage dropped to 0 V. Other parts of the inverter are working: it detects the battery and mains.
The inverter worked completely fine before the code so I suspect the inverter and not the panels.
The inverter worked completely fine before the code so I suspect the inverter and not the panels.