Its a bit unfair to expect folk here to repair your Inverter without some serious information, full schematics, full photos of the PCBs both sides etc, Inverter repairs are not easy.
The HF types, (without a toroid), have many drawbacks, it will do what it can do and no more. Go over the rated so called power rating ie 2000w and it will fail. Surge is also limited.
A HF type is all FETs and if a FET fails the gate is the last to fail.
Here below ..... is a copy of my OzInverter build manual from the tech section, by a good clever engineer in Australia.
"‘Warpspeeds’ comments on limitations of HF (high Frequency) Inverters.
“If you build say a 2Kw high frequency switching power supply to first generate a high dc voltage, and then use PWM to generate a sine wave from that high dc voltage, you are always going to be limited by that 2Kw dc to dc converter.
You cannot suddenly draw 3Kw from it to supply some momentary power surge. There will only ever be 2Kw of dc available.
Now a great steel lump of a transformer driven with PWM straight from a battery is only limited in power by heating of the wire in the transformer, and by the maximum safe current capacity of the mosfets driving that transformer.
Although constant continuous long term power output may still be limited to 2Kw (in this example) you could draw short term power surges of multiples of 2Kw for very short periods without any problem at all.
If you want an inverter that has some real peak surge load grunt, a big lump of iron for the transformer core has all the advantages for a practical inverter.”
‘Warpspeed’ on a Chinese G…..l brand of High Frequency Inverters.
“A High frequency Inverter ……………..It’s the crappy high frequency type that uses five small dc to dc converters in parallel to generate several hundred volts of dc, and then turns that into a modified sine wave. It’s all very highly stressed with light duty parts, and just looking at it the advertised power rating is just a complete total joke.
High frequency inverters are rather fragile and very prone to blowing up. Not necessarily G…..l, but high frequency inverters in general are definitely best avoided.
Much better are the larger transformer inverters, even the modified sinewave types. Better still are the PWM pure sine wave transformer inverters, but all that "goodness" comes at very great extra cost, size, and weight.
A high frequency inverter takes some low voltage dc (12v for G…..l) and generates high voltage dc, usually about 340 volts. It does that with a high frequency switching supply, the G…..l runs about 40Khz, all fairly typical.
Now that is the problem right there. If your switching power supply is designed to deliver 1Kw of power, that is its maximum. It cannot suddenly supply a peak power of 1.1Kw, or 3Kw or 5Kw for a second or two.
Many loads, in fact most loads have high inrush currents when initially switched on, and a high frequency inverter has absolutely zero short term overload capacity, despite what it claims on the front of the inverter.
So you take your 99,000 watt inverter that has a surge capacity of a gazillion watts and plug in one of your power tools pull the trigger, and the smoke escapes from the inverter. Happens all the time...
Now a transformer inverter has a vastly higher overload capacity. It has multiple huge mosfets to ensure low conduction losses, but that also provide massive short term overload capacity. The large transformer and heatsinks can absorb a lot of flash heat, so the inverter will not complain too much about short term overloads.
Now a tiny high frequency switching power supply will have much smaller parts, and just cannot absorb the same type of short term overloads without going bang. Much more stressed, far more fragile. Just a toy really and best avoided for serious usage.”
