Good evening, I want to make my first contribution since a lot of information has been obtained from this forum that has helped me repair some equipment.
Regarding the topic about the mosfets with their numbering erased, I have found a xion brand amplifier with the code A4 and the curious thing about this one is that they did not completely erase the surface of the mosfet, leaving a small detail that I now put in photos
When I dedicated myself to researching on the Internet, I found a page and brand of the possible company that manufactures the type of mosfet. I cannot guarantee that it is the only company, but when reviewing the stock, some values agree or are close to those most used by common brands of the same. form attached page link and make your comparisons I hope the info helps and does not affect anyone
https://wxdh-semi.en.made-in-china....nt-Mode-Power-Mosfet-DSG059n15na-to-220c.html
Although at the moment it would be impossible for anyone other than a company to acquire these spare parts, at least there is data to use and compare with those of other brands and look for a possible substitute.
sorry, I used google translator
Regarding the topic about the mosfets with their numbering erased, I have found a xion brand amplifier with the code A4 and the curious thing about this one is that they did not completely erase the surface of the mosfet, leaving a small detail that I now put in photos
When I dedicated myself to researching on the Internet, I found a page and brand of the possible company that manufactures the type of mosfet. I cannot guarantee that it is the only company, but when reviewing the stock, some values agree or are close to those most used by common brands of the same. form attached page link and make your comparisons I hope the info helps and does not affect anyone
https://wxdh-semi.en.made-in-china....nt-Mode-Power-Mosfet-DSG059n15na-to-220c.html
Although at the moment it would be impossible for anyone other than a company to acquire these spare parts, at least there is data to use and compare with those of other brands and look for a possible substitute.
sorry, I used google translator
There are generally a few different suggestions for various defaced FETs but, as far as I know, no one has done any testing. I think testing would be relatively easy with simple tools that virtually every technician has.
If someone clamped two FETs to a large heatsink (not a clip-on) and connected them in series and drove the gate-source of each with something like their own 9v battery (both new) and drove 30ish amps (could be less) while monitoring the DC voltage across each FETs drain/source, that would tell whether they had the same RDSon, or not (do any of the suggested FETs match the original, defaced FET).
Then you could compare the gate capacitance of each measured to the drain, to the source and then to the drain/source together. Do any match the defaced FET?
You could also drive a square wave of about 25kHz (through a gate resistor of about 47-100 ohms) across the gate/source to see if the waveforms looked the same between the defaced FET and the possible sub.
For the testing to be anywhere near useful, the FETs should be sourced from reputable distributors (more than one) and tested with several of the possible subs and multiple of the defaced FETs if possible,
This may not be definitive but it should get someone close to an exact replacement.
If someone clamped two FETs to a large heatsink (not a clip-on) and connected them in series and drove the gate-source of each with something like their own 9v battery (both new) and drove 30ish amps (could be less) while monitoring the DC voltage across each FETs drain/source, that would tell whether they had the same RDSon, or not (do any of the suggested FETs match the original, defaced FET).
Then you could compare the gate capacitance of each measured to the drain, to the source and then to the drain/source together. Do any match the defaced FET?
You could also drive a square wave of about 25kHz (through a gate resistor of about 47-100 ohms) across the gate/source to see if the waveforms looked the same between the defaced FET and the possible sub.
For the testing to be anywhere near useful, the FETs should be sourced from reputable distributors (more than one) and tested with several of the possible subs and multiple of the defaced FETs if possible,
This may not be definitive but it should get someone close to an exact replacement.