By electrician, are you refering to the solar panel installer or the old electrician, who wotked for the now defunk company?
An inverter should work reliabely for well over 10 years, which begs the question on where you would stand if you bought a newinverter and that to didnt work because of a fault elsewhere like loose or incorrect wiring and or no reliable power from the panals or not enough to kick start start the inverter, after being off, to simply a blown fuse or tripped breaker from the inrush current!
I feel some investigative work (by someone who knows what they are doing) is required before simply going out and buying a new one leaving you potentially being lumbered with the cost of a new inverter, when it might not be needed through lack of contract or incompetence!
What make and model is the inverter?