This TX7 is fully functional and in good condition.
The TX7 is a module version of the full DX7 FM synthesizer engine. 6 Operators, 16 voice polyphony, with MIDI in/out/thru. These are great compact synthesizer expander module for any studio with the ability to load any DX7 preset over Sysex.
Editing the voices will require either a DX7 or a software programmer.