My Superbase Pro 2000 has started making fizzing or frying sounds on the left (AC output) side.

I’ve turned it off and unplugged it for now. For months we’ve had it used as a pass-through UPS for our upright freezer.

What’s going on?

Same here on Superbase V 6400

I did write to Zendure support but didn’t get a reply - do you have an update on this?