Ok so I removed the toroid and attached the blue and red wires to the pcb, and the red and white wires to the coil. Now I'm going to try to close it and that's ready for an analog signal test. Right?
Apart from the fact that the wires were already attached to the pcb (did you take them off?) that sounds right
When I did the previous tests I was doing the tests without the board, when I wanted to remove the board, I didn't see what I was desoldering (I was a bit tired) And desoldered the wrong cables xD So then I had to desolder the right cables and that's how I ended up desoldering all the cables :'D xDD Now I have soldered the cables to the bolts (quite a challenge soldering them without the plastic melting all over) and now it measures 121.5Kohms. No idea what that means, but that's what it is.
In case the thing can't measure an audio tone, could something be done without having to rewind the internal coil?
edit: By the way, how do I test a sound with this? I guess that connecting it to the computer's analog audio isn't working, right? Maybe with some resistor in between? How do I do this? I said I was going to do it but I was thinking connecting it directly to the audio output, which would not be in series, so I guess that's not a possibility