----- Original Message -----

From: Jim Atwood

To: YamahaDX@...

Sent: Sunday, January 02, 2011 10:51 AM

Subject: [YamahaDX] DX-7 MKI Grey Matter E! board problem

?

Hello everyone!

First Happy New Year from Japan.

This evening I tried installing a Grey Matter E! board into my newly acquired used Yamaha DX-7 MKI. The Serial Number is 96982, but I am not sure how to check the OS version number. I believe my DX-7 is ok for installing the Grey Matter E! board but am not %100 sure.

I recently bought the Grey Matter E! board off Ebay. It arrived just fine but I noticed while doing the installation that two "long" screws needed to clamp down the E! board were not sent to me, but I improvised by finding a couple of screws in my spare parts box.

The issue here is that I followed the directions by extracting the two IC chips ( Rom IC14 and Rom IC21 ). I then soldered the red wire to IC63 Pin #7 and the black wire to IC63 Pin #10. I then seated the E! board into the appropriate IC14 and IC21 slots. I was able to do all of this just fine and I thought the board was "snug" enough to warrant turning on the DX-7 for a test run.

Well, after powering up the DX-7, I noticed that I got power but there was no display and the numbers .8 and .68 for example were flickering on and off. It was like there was a short or conflict in the system. I tried re-soldering the wires (carefully!) and re-seating the E! board several times and every time the same thing happened. ( Note I turned off and unplugged everything of course before trying different things ... laugh ).

Thus I was unable to get the Grey Matter E! board to install properly.

One thing I thought of while writing this post is that the when facing the DX-7 ( as if you are going to play the keys ), the IC chips themselves are upside down. My thinking now is that perhaps I soldered the red and black wires opposite of what they should be. IC63 is actually upside down meaning the lettering on the chip itself is upside down. Thus there is hope that if I try this again later in the week, that perhaps that might be the problem. My wires may have been crossed.

Otherwise for now, I re-installed the old chips and restored the voices using DX Manager without any issues. The Yamaha DX-7 works fine, but I just can't seem to understand why the Grey Matter E! board will not work properly.

I will try to find an image on Google ( if lucky ) showcasing the Grey Matter E! board already installed and see how those red and black wires are soldered. If lucky they will be the opposite of what I did. Otherwise ... trash the Grey Matter E! board!! LOL

This was just a small weekend challenge to see if I could add some stuff to the DX-7. If it doesn't work, all is not lost as I will enjoy the stock DX-7 no problem.

If anyone has any other ideas or if you recognize my problem, please let me know.

Thanks!!

Jim

Just an update:

I consulted the manual and noticed that the IC63 chip was oriented a certain way with an indentation on the right side. I can verify that I indeed had the red and black wires soldered correctly. Thus it appears I either made an error somewhere with my soldering or seating the board. It's also possible that the Grey Matter E! board is defective and no longer working properly. I soldered the wires carefully three different times and got the same result. The Grey Matter E! board seemed to also be seated firmly in the sockets as far as I could get them, but I did notice that the screw casing were a bit long. I felt the pins could go deeper if I didn't have the screw casing attached to the E! board. It would be difficult to pry those off though. Still, it should be been seated properly enough I thought, but I could be wrong.

I have no idea how to diagnose the problem at this point so unless I find an angle to test things, I'll probably just file away the Grey Matter E! board and keep the DX-7 stock as it works perfectly and sounds great as is. I don't think I could sell it as I'm unsure at this point whether it works and wouldn't want sell a defective board understandably. Oh well!

Thanks!

Jim