[sdiy] DX7 diagnostics help

[jays at aracnet.com]

mrmike,

I while back I had my DX7II with E! go with a bad battery. I got the corrupted patch names not just a few bad chars but I don't remember not being able to change patches. But it was a while ago.

It looks like Yamaha used a standard button cell that they spot welded their own solder pins on. Or at least I couldn't find a replacement that fit the circuit board pads. I just took a battery holder, soldered wires onto it, put the battery in, heat shrunk that, soldered that to the board and then stuck the heat shrunk unit with double sided sticky tape to the insides.

My DX7II is pretty stationary so I'm not to worried about the heat shrunk battery coming loose on the inside.

Jay S.

mrmike wrote:

> I've got a DX-7IIfd with a Grey Matter E! card in it.  It hasn't been  
> used  in years, but was functioning correctly. I fired it up last night, 
> and it has a problem:
> 
> It boots, and I get the E! v 1.20 message on the LCD. LEDs, etc. seem to 
> be ok.
> Problems:
>       I can't change patches, and the unit produces no sound (at least 
> with this patch).
>      Split mode button looks like it works (two patches appear in LCD)
>      There are some garbage characters at the end of each line in the LCD.
>      Turning the volume up just gives hiss.
> 
> I'm not at all familiar with the E! card, so it could be straight user 
> error. I've found the manual online, but troubleshooting help is sparse 
> there.
> 
> I haven't tested MIDI out.
> 
> Anybody have any suggestions on how to go about fixing this? Should I 
> remove the E! card, or is there some way to reset it? Could this be a 
> battery issue?
> 
> Thanks for any help!
> 
> mrmike