repairing circut

vevor 3500 watt inverter was working well running my all electronics systems and deep freezer as well as my refrigerator and solar panels feeding batts(9) as bank.
the inverter stop out put voltage , but showed it was still on.
I opened the unit ,checked all fuses (good) looking over all parts ant found 1 npn transistor had over heated.
the fan has never come on from day one.
I need a schematics for this unit but not able to find anything on it.
the 4 outlets are wired to half of the system as the term block is feed from both sides of the driver output.
I am going to repair it just would be nice to find a SAMS on the unit .

loved your video so I hope that you can help me find some intell. it is only 2 years old.