Re: Dead DX7 Mark I - Repair questions -- Help!

"[email protected] [YamahaDX]" <[email protected]> 29 Jan 2019 07:21:27 -0800
Newsgroups gmane.music.equipment.yamaha-dx
Message-ID <[email protected]>
You guys are amazing. Thank you across the board! 

 Okay - I'll quickly order a battery holder today and get started this weekend then. Relieved to hear that it's likely E! that's causing the issue and the blinking digits; that's been my thought as well. 
 

 Also, a huge thanks for the link per the ROMs. Given that my ROM burner is on it's way (to try and fix my dead Hammond XB-2), it's good to know that I can ideally burn a ROM if I need it (assuming I learn how to do it correctly)!
 

 From the messages, I figured that removing the E! to first rule things out and bring it back to stock makes sense - at least for troubleshooting. If that's the case, I'm guessing that I will need a replacement EPROM and SRAM.

 

 To be sure, I'll also do some multimeter checks while the DX7 is already open. Hopefully I can make sense of the board; I'm good but not great at that sort of thing.
 

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 Questions at the moment:
 

 1) Which EPROM size should I order? I will already have an extra 27C256 on-hand, as I need that for my Hammond XB-2.

 
2) Which particular SRAM should I order?
 
3) Assuming I figure out to burn EPROMs, which version should I burn? SER-7? Or another version from the forum here (v1.8, v1.9?) I couldn't figure out what's different about each. I read about active sensing, and it would be great to shut that off.


 4) The key thing that I liked about E! was it gave me full 0-127 (not 0-99) per MIDI; will any of the newer ROMs give me that MIDI standard?
 

 5) Assuming I get to the point where I'm ready to format (either via E! or as stock), are there any instructions of how to do so via MIDI SysEx as I don't have a ROM cartridge on-hand? Worried that will be a major road block.
 

 Thanks again, everyone! I'll keep you all posted as to how things go.
 

 - Seth
 

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 PS - Off-topic: Thanks for the slang reminder! Yes, when I said "per," I meant "for." Not sure who used the word "pooch" in this thread, but my DX7 has apparently "screwed the pooch" in this case! LOL. ;)