Re: DX7 Memory Corruption

Alright, I'm a little new to the repair side of this stuff, so I just
wanted to double-check before I start soldering... please let me know if
I'm understanding everything correctly:

It sounds like there are two potential diodes that could be causing this
problem.

First, there is the diode that the battery is normally attached to - D4,
which is a general purpose germanium diode. Anything general purpose diode
could probably be used as a substitute, since the main function is
protecting from reverse current.  However, I should be able to determine
whether this diode is "open" with a simple multimeter check, prior to
replacing it.

The other diode, is labelled ZD1 - and refers to a 6.2 zener diode.
Apparently, this should be located somewhere around the RAM chips (ICs 32
and 4 on the SchematicRotated.pdf) - but I'm having some difficulty finding
it. This diode probably needs to be exactly 6.2v, correct?


Cheers!





On Mon, Sep 3, 2018 at 4:49 PM, charles copp [email protected]
[YamahaDX] <[email protected]> wrote:

>
>
> broken cartridge in the cartridge port?
> or other misdirected connectivity?
> 
>