When you turn the MS2000 on, sysex is disabled by default. This means that each time you turn on the synth, you have to enable sysex for Patch Base to work:
- Press "Global"
- Press Page +/- to get to page 4: MIDI Filter
- Press Cursor > until you get to "SystemEx"
- Press "Yes" to see "ENA", meaning sysex is now enabled
- Press "Exit"