Engineering a part nobody asked for to fix an obsolete welder you can't buy anymore. The DIY ESAB inverter module saga.
Working in the welding business has its benefits. Sometimes you get to keep old welders that are deemed unrepairable. Some times the machine is too cheap to repair so it's uneconomical. Other times the part is no longer sold, so sourcing one is not possible anymore. Well I've happened to receive two welders that are both too expensive to repair and have no parts available. Well, the latter is not entirely true, because the part to fix the welder can still be bought. Unfortunately this part alone costs more than the welder is worth and is increasingly hard to source from the manufacturer. The welders in question are the ESAB CADDY, namely the TIG2200i and another one with more buttons but still based on the same inverter platform. These welders have a funny thing about them - all of the inverter power semiconductors are located entirely in a single module, named the PM1. This module does the input rectification, power factor correction, soft start and has the 2 sw...