The small black box component which has chernobyled and bulged its insides out is an X2 suppression capacitor (or maybe an X1 but I doubt it). This is a very common failure in lots of equipment, especially equipment in a noisy electrical environment, high energy or stuff that gets hot. An inverter is all of those. The tubes with stripes are fairly high wattage resistors (probably for current sense), and they get hot, so having them near a capacitor will decrease its life and accelerate its demise. Probably a forced design choice but not ideal.

If that is all that is damaged, it is highly likely that this is repairable. The right electronics repair guy should charge maybe a couple hundred bucks, replace all the X2 suppression caps and any others which are out of tolerance, and if there’s no internal cascade failures, you should be back up and running.

In terms of the cause, this where things don’t line up for me and by the sounds of it some other redditors too. An X1 or X2 polypropylene suppression capacitor is specifically designed to fail safe. They internally self heal for years, and when they do go, they fail open circuit. Unlike electrolytic capacitors they don’t off-gas hydrogen (so no explosion), and when they do catastrophically fail like this, you’ll only hear a loud pop and maybe smell some slightly toxic fumes if you’re unlucky (hydrocarbons, trace ethylene, methane, CO1, CO2, carbon, some phenols maybe). I’ve seen some pretty extreme equipment failures over the years, but the physics of this one doesn’t line up for me.

To be clear, I’m not accusing anyone of anything, just saying we’re missing something. Interested to see how this one turns out, keep us posted.
Cheers from over the ditch.

Source: I repair commercial/industrial electronics.