Add connectors to the mainboard.

Add cherry switches knobs.

Connect the mainboard and the io board together.

Now, power up your Nava holding the "ENTER" button. LCD should print "TM2 adjustment process". You need to adjust your LCD contrast maybe ;). Adjust TM2 to measure +5.00V at TP1.

Now turn off your Nava then turn on it again holding "START" and "STOP" button. You enter in "Init EEprom mode". You got 5s to press "START" and "ENTER" to init your EEprom. Steps leds show you the progress of the initialization.
Make a Handclap pattern to adjust TM1 handclap offset. Coonect your oscilloscpoe orscope (soundcard oscilloscope to multi out hand clap.

Then adjust TM1 to get 2v P-P wavefrom.

After all this works you finished your Nava v1.0 TR 909 clone. Congratulation! Have fun ;)