It is the first time that I came close to a CTEK Multi XS 7000 battery charger.
The specific unit was operating over a mountain and it duty is the maintenance of the battery of a generator which is capable to feed power in to a mobile network (telephony) transmitter.
By watching few CTEK videos their chargers seems indestructible regarding it output, but this one got killed due the AC Mains input.
I can only do assumptions, as for example that over voltage came in and damaged this IRF830 and this took with it a zener diode and both input fuses.
Or the IRF830 failed just by it self, and caused over current?
The point is that this IRF830 is dead but not smoked or externally damaged.
Either way now I have the hope that by restoring the AC input of this charger, it will get back in action.