> So it seems like the problem is a cooling issue Not just a cooling issue. It's a MOSFET thermal runaway, as it is being driven to its limit, higher temperatu

> So it seems like the problem is a cooling issue Not just a cooling issue. It's a MOSFET thermal runaway, as it is being driven to its limit, higher temperature => higher resistance => higher temperature. It can be stopped by cooling it, but the bigger picture is that it is either being driven improperly, or cheap, low power components are used to cut costs without adequate a safety margin.