On 27 Jun, 2014, at 11:47 PM, zap@... [oberheim] wrote:

Hi Daniel,
thx very much. I will try to figure out by the service manual. But if someone familiar with OB-Xa could give a hint would be very appriciated.  

Good luck with your 6r, i also have one, but it never had a problem.

Cheers,
Stephan