For few month i get a Elka Concorde 811 on ebay, for few euro.
But after the shipment from the seller to me, the item dosn´t work correctly – no sound, but display work, and midi out too.
After long search, i found a schematic of the pcbs in a forum. (analogorgel.de)
So i take a oscilloskop and look for the failure, but no issue found…
So many slotcards are inside… many hours of troubleshooting and no failure found.
A friend of me, a telecommunication engeneer looks inside – and found the failure after 2hours.
The powersupply -12V solderings connections off the voltage controller LM317 are broken.
(1minute soldering fix the issue)