How to continuity test without a multi-meter. The purpose of using a multimeter (in ohms mode) to continuity test is to associate pins and sockets with wire color so you know which ones to swap, and also to verify you've connected them properly.
You don't really need a multimeter. If you have...
Late to the party on this, but FYI, I've had the OPNs now for so many years I can't remember when I got them. Anyhow they are well out of warranty and obviously my model is no longer made. One of mine finally died and have sent it in for possible repair. The other just started acting up...