I see this guy has posted a video on YouTube about connecting this so you might want to watch that to make sure it is connect correctly. Then I would test getting your DX7 to send notes to a software synth, when you get that working then I would work on transferring patches (sysex). Not all devices that handle MIDI connections can handle sysex transfers so you might want to see if Yamaha say it can do sysex. One suggestion is to use Dexed to transfer sounds to your DX7, it is a software synth that emulates a DX7 so you can audition the presets and it also works as a Librarian so you can transfer patches back and forth. Hope that helps.
