From wct@olg.com Fri Feb 07 07:49:12 2003
Subject:Re: my old cx-3 sputtered then died

Shane --

Let me tell you what I did when checking out my CX3. I should say, though,
that I'm not a technician -- just an electronic tinkerer who sometimes gets
lucky.

Just before my CX3 died, it emitted a brief, high-pitched squeal, then went
silent. (I noted that there was still power going to the unit, though,
because the LEDs remained lit.) There are two 40-pin SM-304 chips on the
main board, mounted side by side. With power off, I carefully removed the
SM-304 that is mounted closest to the "drawbar" end of the CX3. I picked
this chip at random, just to see if I could change the symptom by removing it
from the circuit. When I powered the unit on, I had sound: every note on the
keyboard sounded simultaneously and continuously -- as though I were
depressing all the keys at once. Now I, being completely untutored in
matters electronic, but having read that the SM-304 is a parallel-to-serial
converter -- it converts all the note-sounds into a single stream -- figured
I was on to something! So I took a gamble, ordered the chip from Parastream,
plugged it in, and my problem was fixed. I also had to replace the 10-ohm
resistor on the main board (R64 -- the number is printed on the board), which
had been damaged when the SM-304 bought the farm.

Of course, your problem could be caused by something other than one of these
SM 304s. But you say your CX3 made weird sound clusters before dying.
Sounds suspiciously like a parallel-to-serial converter problem...

Regards,

Bill

"shanerettig " wrote:

> Thanks Bill. How could I test my chip to see if it's the problem? I
> want to be sure before I sink $120.
>
> On the parastream products page they mention a cx3
> vibrato/chorus mod. Has anyone here modified their cx3? The
> switches for the weak leslie sim could be used for something
> else.
>
> Shane
>
> --- In CloneWheel@yahoogroups.com, wct wrote:
> > I recently repaired my old CX3 with a chip from Parastream
> Technologies.
> > http://www.parastream.com The typical problem chip is the
> Siemens SM-304.
> > Parastream's replacement chip is $120.00, and is a simple
> plug-in, direct
> > replacement. Depending on the mode of failure of the SM-304,
> you may also
> > have to replace a 10-ohm resistor (R64) on the main board.
> >
> > Regards,
> >
> > Bill
> >
> > "shanerettig " wrote:
> >
> > > Hello
> > > So my old cx3 died. For no apparent reason, it spit awful sick
> > > sounding clusters and then went silent.
> > >
> > > I know this is the $100,000 question, but what's the latest on
> > > those legendary after-market ICs?
> > >
> > > Is there anyone here who has dealt with an old dead cx3? I
> have
> > > some basic electronic skills. Suggestions about where to
> start
> > > troubleshooting would be greatly appreciated!
> > >
> > > Thanks
> > > Shane
> > >
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