SuperSynthProjects makes a DIY project that can be used to rescue a terminal Roland SuperJX when the transformer has burned out. It has been installed and long term tested on JX10/MKS70 and a bare PCB is available. It also has many other potential applications in other synths or modulars

The latest version P0004-04 PCB accommodates replacement of all JX-8P power supply components: Filter, transformer & Linear PSU. Bill of Material contains all variations and options for different display mods plus the JX-8P version

https://supersynthprojects.com/projects/replacement-jx10-mks70-power-supply/