> I bought 2 MN3007 circuit (1024 stages) on eBay and replaced the MN3209
> in one of my 1-88-1Y (256) BBD modules.
> I followed the procedure in the A-188-1 Adjustment Guide
> < http://www.doepfer.de/service/A1881_adjustment.pdf > , but the circuit
> just sat there. Seems like I did everything right, I switched back to
> the 3209 and it worked, then back to the 3007 (making the appropriate
> jumper adjustments and all), but I got no sound at all from the MN3007.
>
> Is there something else I should be doing or could my chips be dead

I do not want to blame a reliable Ebayer (provided that he/she is) and I'm
not sure if this applies in your case and but there were counterfeit BBD
circuits offered in Ebay. Any low circuits were re-labelled as BBD circuits.
We had to scrap 150 counterfeit BBD circuits ordered via Ebay when we
started the A-188-1 production.

But if you followed the A-188-1 adjustment/replacement guide and then
switched back successfully to the MN3209 I'd guess that the MN3007 are
defective.

Best wishes
Dieter Doepfer