Serge Positive Slew - Paperface - restoration

Some pics of the Positive Slew.
This is from panel 2.1 (Warren Burt paperface).

 The red IC socket holds a LM3900 opamp which I swapped.
No improvement though. :-(
The module is powered by -12V (bottom blue), +6V (Green), +12V (Red), 0V (Blue top)

Connecting the lower pulse output to START or SUSTAIN should cause the Positive Slew to operate as a VCO or LFO..




The module uses two OpAmp ICs:
a  LN3900 & a MC 3401

The above pin out is for the MC 3401

It's interesting that both Quad op amps have identical pinouts


Links:
1. Ken Stones CGS - Positive Slew
2. DUSG - CGS 
3. Serge.synth.net