Old Sussex Valve tester

[Bushbaby]

This is getting weird for me! I've connected a multimeter probe to the soldered pink wire of the cap and touched it with the other probe and of course a noise occurred to demo continuity. It appears that the pink wire is linked to the Canon 50 way connector (see pics). I have tried my best to carefully touch the end of the multimeter probe to the connections...NO response. In the middle row, I placed a thin piece of wire into each mini socket of this level and touched again with the probe...NO response again. Is there a better way of doing this at all?

Thanks