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).]

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.
That's ok, I have the original voice cartridge.

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.
Unfortunately, that's not working on my DX7.

I've also heard that similarly pressing Function/16/32 provides access to diagnostics.
Well, that's working, but isn't giving me any needed information.

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.
The battery is ok, "battery check" function gives 2.8 Volts

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.
Could that be one way to reset the device? If the battery is removed, all the data in the RAM should be erased...

One solution to the problem could be the E! board and it would also give some extra functionality to my dx7. Unfortunately they are very hard to find these days, I assume.

Maybe I'll try to remove the battery, unless someone advises me NOT to do so...

Thanks!

The MIDI problem you are seeing is very strange and sounds more like a circuit problem than a software problem in which case adding an E! board probably wouldn't help and I don't think your chances of finding one of those a very good. About the only one you would be likely to get would be buying another DX7 with one installed.

While I don't think removing the battery will solve the problem you may as well try it.