Sounds like it might be dead. Obviously he could go deeper and check behind the gfci or open it up and look for burnt mosfets. but typically if a inverter has gfci's on them they are cheap to start with.
Its hard to say with out more info.
If it is a MSW upgrading to PSW is highly recommended and would certify the old one was a cheap inverter to start with. modified sine wave is the cheapest of cheap inverters
The real question is what are u getting for 2500$ hopefully a magnum, victron multiplex, or other really really high end DIRECT wire no gfci psw inverter otherwise total ripoff for say a cheapy gfci 500$ amazon special.
the blinking light and other weird things are just side effects of a failing inverter. shore might not correct it as certain circuits are dedicated from the inverter.
The "right inverter" can easily cost 2k or in that neighborhood.
depends on what all your inverter is running
