1) I have the user's manual and the service manual in pdf format.
Okay, otherwise I was going to tell you where you could find them.

2) No, because I don't know how to do it. I couldn't find any instructions anywhere.
First, I should warn you that a reset will initialize all the user data, which means there will be no voice patches loaded when you are done. You probably shouldn't try this unless you have the original voice ROM, since if the reset doesn't fix the MIDI problem you won't have a way of reloading. I don't own a DX7 myself, but I've heard that pressing and holding down the "Edit", "16", and finally "32" buttons and then releasing them all will get you to the reset. I've also heard that similarly pressing Function/16/32 provides access to diagnostics.

Hopefully, Steve (who is Yamaha's tech guy) can verify (or deny) this info.

3) Ummm... do you mean the readout of the lcd display or the readout of the midi software? After pressing the Function button, there is a text "FUNCTION CONTROL | MASTER TUNE ADJ" in the lcd. The software doesn't react at all.
I meant the LCD; I asked because I wanted to determine if your unit had a Grey Matter E! board in it. From your response, apparently it doesn't.

4) No modification or damage can be seen.

Well, hopefully that leaves out problems caused by physical shock or the like.

The DX7 has a lithium battery used for RAM back-up purposes. The don't usually last more than about 10 years, although sometimes a bit longer. I'm not familiar enough with the DX7 to know if strange behavior could be related to a weak (or leaking?) battery, especially if the user data isn't being lost when the synth is off. Perhaps Steve could weigh in on this as well.

Good luck with your problem.

--Barry


[This message has been edited by quietDIN (edited 02-20-2005).]