14
Front panel assembly
3.1 - Inspection & cleanup
Congratulations! You've finished the soldering and have earned a break. Drink some tea, take a
nap, etc, because there's a little more work to do and it's not a good idea to rush through it.
When you're refreshed and ready, take this chance to perform a thorough visual inspection of
both PCBs. Use bright light and magnification to inspect all of the solder joints, and use a felt-tip
marker to mark which ones you think need extra attention (there are always a few!). Apply some
flux, use more solder, reflow, or use desoldering braid as needed to clean up the joints.
When you are satisfied with your soldering, clean up any flux residue from both PCBs using an
old toothbrush and some isopropyl alcohol. Blot the boards dry with a paper towel and let them
sit for 15-20 minutes to dry fully.
3.2 - Electrical and functional tests
Before applying any power to the module, you should first check for short circuits. Use a
multimeter in continuity mode with an audible buzzer.
1. On the CPU board, test for any shorts between the center pins of the power connector
and the outer pins of the power connector (b12v / GND, and -12V / GND).
2. On the CPU board, test for shorts between any of the legs of the larger LM7805 voltage
regulator (b5V/GND, +12V/+5V, and +12V/GND).
3. On the Control board, test for shorts between the outer two legs of any potentiometer,
e.g. RV1. (b5V/GND). With the knob turned all the way left or right, you will find a
short between the middle leg of the potentiometer and one outer leg - this is normal.
Once you are satisfied, attach the 2nd hex standoff to one of the PCBs by inserting a screw
through one of the mounting holes near the middle of each PCB, and threading on the hex
standoff on the underside of the board. Mate the two boards together using the header pins,
and insert a screw into the other side of the standoff. Do not overtighten! You can flex or crack
the board if you are not careful.
Now, at last, you can power up the board by connecting it to a eurorack power supply, being
careful to observe the polarity of the power connector. You should see the display light up and
the LEDs begin blinking. Check that all of the knobs and buttons are working!
