Are you able to see why it failed? Have you had the recommended Annual Routine Maintenance carried out? I just ask this as on reading their manual (http://sol-distribution.com.au/ABB/Installation%20Manual/abb-pvi-3-3.6-4.2kw-inverter-installation-manual.pdf) in Chapter 8 it states:
"Checking and maintenance operations must be carried out by specialized
staff assigned to carry out this work."
Scheduled maintenance operations are not mandatory, but are recommended to preserve the efficiency of the PV plant.
We recommend that maintenance operations be carried out by qualified personnel or by the personnel of ABB (as set forth in a maintenance contract).
The periodicity of the maintenance operations may vary in accordance with local environmental conditions and the installation"
Annual visual inspection
• Check that the inverter is operating correctly, and that no fault alarms are present
• Ensure all the labels and safety symbols are visible
• Test the integrity of the cables, connectors, and plugs external to the inverter
• Check that the environmental conditions have not changed drastically since
the installation of the system
• Check that cable glands and connection block screws are tight
• Check that the wiring box cover is properly closed
• If no monitoring system is present, check the history log of alarms and errors
using the instructions given in the manual in order to look for recent malfunction
• Clean the equipment; in particular the bottom grille of the wiring box and the
& from page 82 to 88 it lists all the fault messages and led lamp states (if fitted)
Together that might help you identify why it has failed (if you wanted to know).
I have provided this just in case you weren't aware of these things.