while ago I've bought an DS-2 at Ebay. When it arrived
here nothing was working... :(
the former owner didn't mentioned it wasn't working... but,
thats ebay and it was quite cheap.
On the first look at the inner life I saw the
- The DS2 has some kind of 'slot in' card system, but you can't screw
the cards in, like in a PC. And what happes if you don't use screws on
the cards in your PC? Exactly, they get loose (especially when shipped
with the 'good' service from the german mail.)
The same goes for the DS2 - the cards were not stuck propperly into
their slots... so the first thing to do was to reconnect all the
cards in the DS2.
But my Crumar remained silent. no blinkenlights, no noise, nothing...
So I checked the PSU but my DMM showed the normal +/- 12V and +5V...
I gave it to a friend to have a look at it, cause i was clueless.
He figured out it WAS the PSU, changed the regulators and it worked
After the PSU was working again, the big synth had to return to my home
(strange looking taxi driver included because I don't own a car)
to have a coser look at it.
Now nearly everything
Remaining bugs were:
- the synth always
played the lower F
- the two envelopes
were stuck in sustain phase
First I thought the
envelope circuit was faulty (P440).
But this wasn't the case. So I went over to check the gate Signal
(thanks to SDIY mailinglist)
BINGO! No gate
signal. So I checked the keyboard control.
Following the cable
for the gate signal, I ended at the "Memorized
Keyboard Code" PCB P431.
Cleaning of the IC's
and sockets had no effect (very often it's a
mechanical and not an electronic problem, so clean the contacts) ) so I
just changed all the IC's on P431 cause all are still available
and in sockets, so they were easy to change.
And now, after this
little IC change procedure, my DS2 is working fine.
LFO 1 is stuck
sometimes :( and the polymode has a fault. sometimes it
just goes silent. touching the poly mode pcb helps, but I didn't
figuered out where the cold solder joint or whatever is.
But what was it ALF
said?: "If I can't fix it, it isn't broken" ;)