Check that the two 'jumpers' at ST3 and ST4 are in still in place -
these connect the internal oscillator to the rest of the shifting
circuit. The location of these two are shown in this document, as it is
where you can connect an external oscillator up, such as the A-143-9:

http://www.doepfer.de/a100_man/A126_A143_9_connection.pdf

Also check that the socketed ICs are firmly seated, by gently pushing
on them, particularly the PA382/CEM3382, as this *is* the oscillator.

Tim

--- In Doepfer_a100@yahoogroups.com , dab <trafo-dab@...> wrote:
>
> my a126 freq shifter suddenly stopped doing his job.
> the audio output still works at normal level but the 3 shifted outs
(up,
> down and mixed) are very silent
> and there is no effect to be heard anymore.
> the overload starts clipping at 3 already - input is an osc sawtooth
> directly.
> when the mix poti is in middle setting - the signal is almost mute,
> extreme left and extreme right does give
> a very silent signal.
>
> anybody has an idea what could be the problem
>