The cables are working ok, that's for sure. I had a midi keyboard few years ago and everything worked fine.

I built a simple midi tester that blinks a led when there is coming signal from the dx7. Indeed, it seems that there is some activity all the time. Must be the active sensing thing...

The sysex sending/receiving tools (Midilib, DX manager, MIDIOX) I have been using doesn't apparently show these active sensing messages. I also wasn't able to find a way to filter them out. Is there any recommended software for monitoring midi messages?

Thank you!