You lost all power when plugged into shore power?
That doesn't sound like the inverter, it sounds like the MAIN circuit breaker in your power panel. I don't know where the main breaker panel is in your RV but it should be obvious, typically located near the floor with a vented brown cover, maybe 10" x 10"
Again, not sure where that panel is, but the inverter in most models is mounted near it, but inside wherever that power panel is. For example, if the power panel is located on the side of the bed, you remove the mattresses and the plywood the mattress lays on. Since your bed is on a slide out... It's unlikely the power panel and inverter are there on your model.