Good morning everyone,

This morning at around 05:20 wife and I were sitting in bed, enjoying the morning coffee, and the lights and fans went off.  At first I thought the power was out again, but then the inverter should have kicked in.  Anyway, I investigated, noticed the battery is flat and the inverter switched off.  I did my dues, switched off everything and switched it back on one by one.  Nothing.  The inverter was quite warm to the touch which shouldn't be at this time of the morning (battery should be full, inverter only passing through Eskom).

I left it all off for an hour, including the mains to the inverter (Eskom to Inverter breaker) and switched it back on.  I tried switching on everything but nada.

5 minutes later the inverter is hot to the touch and the classic magic smoke smell is apparent.  Inverter is fried.  What would the problem be?  It's installed indoors, so insects and so on isn't a problem, and they're supposed to be quite hardy inverters, no?  The inverter is less than 3 years old, but obviously out of warranty.  Could it be fixed, is it an expensive fix, what could be the issue, etc?  I'm getting a temp installed this afternoon just so we can have lights and fans in the house again, but I'd like to have this one fixed if possible.

Once the magic smoke has been let out there's not much you can do but send it in for repair to see what failed

Yes, they do fail, some of them truck on for years.

Have you ever cleaned out the air vents? They do get clogged with dust over time

At a wild guess: the capacitors protecting the MOSFETs dried out and failed to suppress spikes as is their duty. That caused the MOSFETs to fail shorted. This is usually accompanied by a loud bang and the smell of burned epoxy. Would you have heard a loud bang, or is the inverter a fair way from where you were?

Is it fairly hot where you are located? Higher ambient temperatures do accelerate the aging of components, and it's often the capacitors that go first.

You mentioned fans, suggesting that the climate is hot.

The Axpert inverters are pretty good considering their low price point but I'd say they're not worth fixing unless you do that kinda thing already as a hobby and fancy a challenge to keep you out of the pubs for a while. What happened to you is exactly the same issue that prompted me to join this forum (hence my profile pic) and whilst eventually I managed to repair my inverter it it was a learning curve that took enormous amounts of time and resulted in several new grey hairs a pile of blown AliExpress replacement componentss before I had sucess.

 

I was fortunate in that I have a repair bench with an oscilloscope and test equipment, I have experience with component level board repairs and a library of information and datasheets I've collected over the decades. Even so, with hindsight it was a job I wouldn't take on again and I wouldn't recommend others attempt themselves. I can almost 100% guarantee you it won't just be the MOSFET that's failed in isolation.