Well, to test the 3340 you basically have to wire it up as an oscillator, which you have done already 
Are you seeing the correct waveforms but at 1/3 Hz or so? That could be that you’ve lost all CV inputs (or as likely, fried the summing amplifier in the 3340).
You can check this by measuring the voltages before the 100k resistors that are connected to pin 15; e.g. for the stripboard layout you can measure the voltages at either point A or B in the drawing here:
You want at least a few volts in total to get an audible signal; for something like 440 Hz you need just over 9 V or so (see here).