After the device has been overturned and slammed on hard tile floor (the device is actually stable, but children do anything), was indeed externally to detect any damage, but the engine mount inside was broken. Many other devices, this would have been a total loss as to get difficult to spare parts. Not so with this unit. An email to the manufacturer, and 2 days later I had a new engine mount at a fair price and was afloat again the device.