My dead welder has mosfets labeled as TOSHIBA K2837. After an extensive 3 week search, I found data sheets with conflicting information. Until today, I could not know which ones were accurate. Now, I know why no one was able to offer help. Several sheets showed K2837 with exact specs to the Toshiba 2SK2837. Other sheets showed values that had higher values than the 2SK2837. I convinced myself that any mosfet labeled as "K2837" could not be trusted and were likely conterfeit. So, I decided to search for a mosfet with the higher Amp and higher Watt specs that were showing up. I wasted many hours. I could not find any mosfet labeled as K2837, that had higher values, and all were showing specs for the 2SK2837. Today, I decided to compare the physical part I have, to the images shown on the spec sheets I found. The actual part on my welder matches exactly to the physical shape being illustrated on the 2SK2837 spec sheets. Had I thought of looking beyond the numbers, I could have saved myself a lot of time! Turns out the datasheets are NOT for comparing specs alone. The images matter. The image shown on the K2837 sheets with higher values, does not look like my part. What a surprise it was to learn that all along that I actually have and need to find replacement 2SK2837 mosfets!
I found the FQA24N50 is nearly a perfect match to those higher values spec sheets. Those higher values consist of 271W versus 150W, 24A v 20A, and many other specs vary, see the attached data sheets below, for the K2837, the 2SK2837, and the FQA24N50 mosfets.
Before I go and buy a dozen 2SK2837 mosfets as replacements, what if any, would be considered a better/stronger/more durable mosfet to use in a multiprocess welder (model is analog "SUPER-200P")? Could a "stronger" mosfet, as the FQA24N50 mosfet be used, or would it cascade detrimental damage to other components?
Without feedback, I am looking to purchase a dozen 2SK2837 mosfets to start repairing and rebuilding my Upper Board.
Thanks.